CN223273294U - Battery cells, battery devices and power-consuming devices - Google Patents

Abstract

The application belongs to the technical field of batteries, and particularly relates to a battery unit, a battery device and an electric device, wherein the battery unit comprises a shell and an electrode assembly, the shell is provided with an electrode lead-out part, at least part of the electrode assembly is accommodated in the shell, the electrode assembly comprises a first electrode plate and a first insulating piece, the first electrode plate comprises a conductive member, a current collector and an active material layer, the current collector comprises an insulating substrate and a metal layer, the metal layer comprises a main body part, the main body part comprises a transition part and a conductive part, at least part of the conductive part is covered with the active material layer, the transition part is not covered with the active material layer, the conductive member comprises a first connecting part connected with the metal layer and a second connecting part electrically connected with the electrode lead-out part, the first connecting part comprises a first connecting part, the first connecting part covers the surface of the transition part facing away from the insulating substrate, and the first insulating piece protrudes out of the edge of the active material layer along the direction of the conductive part, so that the short circuit risk of the battery unit is reduced.

Description

Battery cell, battery device and electricity utilization device

The present application claims priority from international patent application PCT/CN2024/106988 entitled "battery cell, battery device and electric device" filed on month 07 of 2024, the entire contents of which are incorporated herein by reference.

Technical Field

The application belongs to the technical field of batteries, and particularly relates to a battery cell, a battery device and an electricity utilization device.

Background

Battery cells are widely used in electronic devices such as cellular phones, notebook computers, battery cars, electric vehicles, electric airplanes, electric ships, electric toy vehicles, electric toy ships, electric toy airplanes, electric tools, and the like.

The battery device comprises one or more battery cells to meet the use requirements of different electric capacities, but in the technology of the battery cells, how to improve the use reliability of the battery cells is an important research direction.

The statements made above merely serve to provide background information related to the present disclosure and may not necessarily constitute prior art.

Disclosure of utility model

The embodiment of the application aims to provide a battery cell, a battery device and an electric device, which can improve the use reliability of the battery cell.

The technical scheme adopted by the embodiment of the application is as follows:

In some embodiments, the battery cell comprises a shell and an electrode assembly, the shell is provided with an electrode lead-out part, at least part of the electrode assembly is accommodated in the shell, the electrode assembly comprises a first pole piece and a first insulating piece, the first pole piece comprises a conductive component, a current collector and an active substance layer, the current collector comprises an insulating base and a metal layer, the insulating base, the metal layer and the active substance layer are arranged in a stacking mode along the thickness direction of the current collector, at least part of the metal layer is located between the insulating base and the active substance layer, the metal layer comprises a main body part, the main body part comprises transition parts and conductive parts which are arranged and connected in a first direction, the first direction is perpendicular to the thickness direction of the current collector, at least part of the conductive parts is covered with the active substance layer, the transition parts are not covered with the active substance layer, the conductive component comprises a first connecting part and at least one second connecting part, the first connecting part is connected with the metal layer, the second connecting part is electrically connected with the electrode lead-out part, the first connecting part comprises a first connecting part, the first connecting part covers the surface of the transition part faces the insulating base, the transition part, the first connecting part faces the active substance layer, the first connecting part is located on the surface of the insulating base, the first connecting part, the active part is located on the side, the first connecting part, and the conductive part is located on the first connecting part, and the conductive part is located on the side, and the active part is far from the edge of the active part.

In addition, the current collector adopts a composite structure of an insulating matrix and a metal layer, the metal layer is smaller than that of a pure metal current collector, burrs generated in the manufacturing process of the current collector are smaller, the internal short-circuit risk of the battery is reduced, and the use reliability of the battery is improved.

In some embodiments, the first insulating member projects from the first connection sub-portion near an edge of the active material layer in a direction in which the transition portion points toward the conductive portion.

By adopting the technical scheme of the embodiment, the first insulating piece can cover the edge of the first connecting sub-part close to the active material layer, thereby blocking parts such as burrs, metal fragments and the like at the edge of the first connecting sub-part close to the active material layer, reducing the short circuit risk of the battery cell and improving the use reliability of the battery cell.

In some embodiments, in the first direction, an edge of the transition portion distal from the conductive portion is flush with an edge of the first connection sub-portion distal from the active material layer.

According to the technical scheme, along the first direction, the edge of the transition part far away from the conductive part is flush with the edge of the first connecting sub part far away from the active material layer, the first pole piece is regular in structure and convenient to process and manufacture, redundancy of the first connecting sub part or the transition part can be reduced, space is saved, the energy density of the battery cell is improved, in addition, the first insulating piece also protrudes out of the edge of the transition part far away from the active material layer, burrs, metal fragments and other parts of the edge of the transition part far away from the active material layer are blocked, the short circuit risk of the battery cell is reduced, and the use reliability of the battery cell is improved.

In some embodiments, the conductive portion has a dimension L ₁ and the transition portion has a dimension L ₂,0.8≤L₂/L₁≤1 in a second direction, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector.

By adopting the technical scheme of the embodiment, the design of L ₂/L₁ which is more than or equal to 0.8 and less than or equal to 1 ensures that the size of the transition part along the second direction is large, thereby being beneficial to improving the connection area between the first connection sub-part and the transition part, improving the overcurrent capacity of the first pole piece, reducing the heat generation of the battery cell and improving the quick charge performance of the battery cell.

In some embodiments, the first connection portion is welded to a surface of the metal layer facing away from the insulating substrate to form a first solder mark, and the first solder mark is located on a side of the active material layer near the transition portion along the first direction.

By adopting the technical scheme of the embodiment, the first connecting part is welded on the metal layer, the welding operation is simple, the manufacture and the processing of the first pole piece are convenient, and the first welding mark is positioned on one side of the active material layer close to the transition part, so that the first welding mark is separated from the active material layer, the risk of cold welding of the first connecting part and the metal layer caused by the active material layer is reduced, and the use reliability of the battery cell is improved.

In some embodiments, the first insulating member covers at least a portion of the first solder print.

By adopting the technical scheme of the embodiment, the first insulating piece can block parts such as burrs, metal chips and the like on the first welding print, reduce the short circuit risk of the battery cell and improve the use reliability of the battery cell.

In some embodiments, the first solder comprises a first solder portion, and the first connection sub-portion is soldered to a surface of the transition portion facing away from the insulating substrate and forms the first solder portion.

By adopting the technical scheme of the embodiment, the first connecting sub-part is welded with the transition part, so that current can directly flow to the conductive member through the transition part, thereby being beneficial to improving the overcurrent capacity of the first pole piece and improving the quick charge performance of the battery cell.

In some embodiments, the transition portion has a dimension L ₂ and the first solder portion has a dimension L ₃,0.8≤L₃/L₂≤1 in a second direction, wherein the second direction is perpendicular to the first direction and the thickness direction of the current collector.

By adopting the technical scheme of the embodiment, the design of L ₃/L₂ which is more than or equal to 0.8 and less than or equal to 1 ensures that the size of the first welding part along the second direction is larger, thereby being beneficial to improving the connection area between the first connector part and the transition part, improving the overcurrent capacity of the connection part of the first connector part and the transition part, improving the overcurrent capacity of the first pole piece, reducing the heating of the battery monomer and improving the quick charge performance of the battery monomer.

In some embodiments, the first insulating member covers at least a portion of the first solder joint.

By adopting the technical scheme of the embodiment, the first insulating piece can block parts such as burrs, metal chips and the like on the first welding part, reduce the short circuit risk of the battery cell and improve the use reliability of the battery cell.

In some embodiments, the first insulator projects the first solder proximate to an edge of the active material layer in a direction in which the transition points toward the conductive portion, and/or the first insulator projects the first solder distal to an edge of the active material layer in a direction in which the conductive portion points toward the transition.

By adopting the technical scheme of the embodiment, the first insulating piece can cover the edges of the first welding parts which are relatively distributed along the first direction, and can block burrs, metal scraps and other parts at the edges of the first welding parts which are relatively distributed along the first direction, so that the short circuit risk of the battery cell is effectively reduced, and the use reliability of the battery cell is improved.

In some embodiments, an edge of the first solder portion distal from the active material layer is flush with an edge of the first connector portion distal from the active material layer in the first direction.

According to the technical scheme, the edge of the first welding part, which is far away from the active material layer, is flush with the edge of the first connecting sub-part, which is far away from the active material layer, along the first direction, the first pole piece is regular in structure, so that the processing and manufacturing of the first pole piece can be facilitated, the redundancy of the first connecting sub-part can be reduced, the space is saved, the energy density of a battery cell is improved, in addition, the first insulating part is also protruded out of the edge of the first welding part, which is far away from the active material layer, and the first insulating part can cover the edge of the first welding part, which is far away from the active material layer, so that burrs of the edge of the first welding part, which is far away from the active material layer, can be blocked, the short-circuit risk of the battery cell is reduced, and the use reliability of the battery cell is improved.

In some embodiments, along the second direction, opposite edges of the transition portion are respectively flush with opposite edges of the first connection sub-portion, and opposite edges of the first solder portion are respectively flush with opposite edges of the first connection sub-portion.

By adopting the technical scheme of the embodiment, the two side surfaces of the first pole piece, which are distributed oppositely along the second direction, have regular structures, so that the processing and the manufacturing of the first pole piece can be facilitated, the redundancy of the first connecting sub-part and the transition part can be reduced, the space is saved, the energy density of the battery cell is improved, in addition, the size of the first welding part is equal to the size of the transition part along the second direction, the welding area between the transition part and the first connecting sub-part is increased, the overcurrent capacity of the first pole piece is improved, and the quick charging performance of the battery cell is improved.

In some embodiments, the metal layer further comprises at least one protruding portion, the transition portion is connected between the protruding portion and the conductive portion, the sum of the dimensions of all protruding portions is smaller than the dimension of the transition portion along a second direction, the second direction is perpendicular to the thickness direction of the current collector, the first connecting portion comprises at least one second connecting sub-portion, the second connecting sub-portion is connected between the first connecting sub-portion and the second connecting portion, the second connecting sub-portion covers the surface of the protruding portion, facing away from the insulating substrate, and the second connecting sub-portions and the protruding portions are in one-to-one correspondence.

In addition, the protruding part can also be connected with the second connecting sub-part, thereby increasing the connection area of the metal layer and the first connecting part, improving the overcurrent capacity between the metal layer and the first connecting part and improving the quick charge performance of the battery monomer.

In some embodiments, the first solder comprises at least one second solder portion, the second connector portion being soldered to the corresponding protrusion and forming one second solder portion.

By adopting the technical scheme of the embodiment, the second connecting sub-part is welded with the protruding part, and the connection of the first connecting part and the metal layer can be realized.

In some embodiments, the first insulating member covers at least a portion of the second solder joint.

By adopting the technical scheme of the embodiment, the first insulating piece can block parts such as burrs, metal chips and the like on the second welding part, reduce the short circuit risk of the battery cell and improve the use reliability of the battery cell.

In some embodiments, the first insulator projects the second solder closer to the edge of the active material layer in a direction in which the transition points toward the conductive portion, and/or the first insulator projects the second solder farther from the edge of the active material layer in a direction in which the conductive portion points toward the transition.

By adopting the technical scheme of the embodiment, the first insulating piece can cover the edges of the second welding parts which are distributed relatively along the first direction, and can block burrs, metal scraps and other parts at the edges of the second welding parts which are distributed relatively along the first direction, so that the short circuit risk of the battery cell is effectively reduced, and the use reliability of the battery cell is improved.

In some embodiments, the first insulator projects the second connector portion closer to the edge of the active material layer in a direction in which the transition portion points toward the conductive portion, and/or the first insulator projects the second connector portion farther from the edge of the active material layer in a direction in which the conductive portion points toward the transition portion.

By adopting the technical scheme of the embodiment, the first insulating piece can cover the edges of the second connecting sub-parts which are distributed relatively along the first direction, and can block burrs, metal fragments and other parts at the edges of the second connecting sub-parts which are distributed relatively along the first direction, so that the short circuit risk of the battery cell is effectively reduced, and the use reliability of the battery cell is improved.

In some embodiments, the first insulating member includes a first insulating portion and at least one second insulating portion, the first insulating portion covers the first connector portion, the second insulating portion covers the second connector portion, and the second insulating portion corresponds to the second connector portion one to one.

Through adopting the technical scheme of this embodiment, first insulator can cover first connector portion and second connector portion, has increased the coverage area of first insulator, improves the insulating effect of first insulator, has reduced the free short circuit risk of battery, improves the free reliability in use of battery.

In some embodiments, at least one of the opposite side portions of the first insulating portion protrudes from a corresponding side of the first connection sub-portion along the second direction.

By adopting the technical scheme of the embodiment, the first insulating part can block burrs at the side face of the first connecting sub part along the second direction, so that the short circuit risk of the battery cell can be reduced, and the use reliability of the battery cell can be improved.

In some embodiments, the number of the protruding portions is a plurality, the number of the second connection sub-portions is a plurality, the plurality of protruding portions are arranged at intervals along the second direction, the plurality of second connection sub-portions are arranged at intervals along the second direction, the plurality of protruding portions and the plurality of second connection sub-portions are arranged in a one-to-one correspondence, the plurality of second connection portions are arranged at intervals along the second direction, the second connection sub-portions are connected with the second connection portions in a one-to-one correspondence, the plurality of second connection sub-portions are connected to the edge of the first connection sub-portion, which faces away from the active material layer, the first connection sub-portions are arranged continuously along the second direction, the number of the second insulation portions is a plurality, the plurality of second insulation portions are arranged along the second direction, and the second insulation portions are in one-to-one correspondence with the second connection sub-portions.

According to the technical scheme, the first connecting sub-part is arranged continuously along the second direction, the plurality of second connecting sub-parts can be connected into a whole, the first connecting sub-part can play a good supporting role on the second connecting sub-part, the risk of inserting the second connecting sub-part between the first pole piece and the second pole piece when bending can be reduced, the short circuit risk of the battery cell is reduced, the use reliability of the battery cell is improved, the first connecting sub-part is large in size along the second direction, the welding area between the first connecting sub-part and the transition part is improved, the overcurrent capacity of the first pole piece is improved, the quick charge performance and the use reliability of the battery cell are improved, the plurality of protruding parts are arranged at intervals along the second direction, the main body part is divided into a plurality of areas along the second direction, one area can correspond to one protruding part, electrons in each area can be transmitted to the electrode lead-out part through the corresponding protruding part, the electronic transmission area of the main body part can be realized, the electronic transmission area in each protruding area can be reduced to the corresponding electronic transmission area of the electrode cell, the whole transmission path is shortened, the quick charge performance of the battery cell is improved, and the whole transmission path can be reduced, and the reliability of the battery cell is improved.

In some embodiments, two adjacent second insulating portions meet.

By adopting the technical scheme of the embodiment, two adjacent second insulating parts can be directly connected to form an integral structure, the installation of the first insulating part can be facilitated, meanwhile, the second insulating parts can also cover the two opposite edges of the second connecting sub-part along the second direction, the parts such as the tip bulges and the metal fragments at the two opposite side surfaces of the second connecting sub-part along the second direction are blocked, the short circuit risk of the battery cell is improved, and the use reliability of the battery cell is improved.

In some embodiments, the first solder print and the active material layer are spaced apart along the first direction.

By adopting the technical scheme of the embodiment, a gap exists between the first welding mark and the active material layer, so that the first connecting part and the metal layer are not welded to the active material layer, the risk of cold joint of the first connecting part and the metal layer is reduced, and the use reliability of the battery cell is improved.

In some embodiments, the first solder print is spaced from the active material layer by S ₁ in a first direction, where 0.3 mm≤S ₁≤5 mm, optionally 0.5 mm≤S ₁≤2.8 mm.

By adopting the technical scheme of the embodiment, the S ₁ mm which is more than or equal to 0.3mm and less than or equal to 5mm is adopted, so that the first welding mark can not be welded on the active material layer, the virtual welding risk of the first connecting part and the metal layer is reduced, the connection reliability of the first connecting part and the metal layer is favorably improved, the use reliability of the battery monomer is improved, in addition, the distance between the active material layer and the first welding mark is reasonable, the distance between the active material layer and the first welding mark is relatively short, and under the condition that the size of the metal layer in the first direction is certain, the area which can be covered by the active material layer is more, and the energy density of the battery monomer is favorably improved.

In some embodiments, the electrode assembly includes a second insulator covering a surface of the metal layer facing away from the insulating substrate, the entire second insulator being located between the first solder and the active material layer.

By adopting the technical scheme of the embodiment, the second insulating piece covers the part of the metal layer between the first welding mark and the active material layer, so that the insulation of the part can be realized, the short circuit risk of the battery cell is reduced, and the use reliability of the battery cell is improved.

In some embodiments, the first connection sub-portion is spaced apart from the active material layer along the first direction.

By adopting the technical scheme of the embodiment, the first connecting part is not contacted with the active material layer, so that the mutual influence between the first connecting part and the active material layer can be reduced, and the performance of the battery cell can be improved.

In some embodiments, at least a portion of the second insulator is located between the first connector portion and the active material layer.

By adopting the technical scheme of the embodiment, the second insulating piece covers the part of the transition part between the first connecting sub-part and the active material layer, and the second insulating piece can play a supporting role on the part, so that the risk of cracking of the part is reduced, in addition, the second insulating piece covers the part of the transition part between the first connecting sub-part and the active material layer, the insulation of the part can be realized, the short circuit risk of the battery cell is reduced, and the use reliability of the battery cell is improved.

In some embodiments, the electrode assembly further comprises a second pole piece with polarity opposite to that of the first pole piece, the second pole piece comprises a main body functional part and a pole lug part, the main body functional part is provided with a first end face at the end part close to the transition part, the pole lug part extends outwards from the first end face, and the projection of the first end face is located in the projection of the second insulating part along the thickness direction of the current collector.

Through adopting the technical scheme of this embodiment, first terminal surface and the relative setting of second insulating part, the burr of second insulating part accessible first terminal surface department reduces the free short circuit risk of battery, improves the free reliability in use of battery.

In some embodiments, along the first direction, one side of the first insulating member covers the first connection sub-portion, and the other side of the first insulating member covers at least a portion of the second insulating member.

By adopting the technical scheme of the embodiment, the first insulating piece and the second insulating piece can realize double-layer insulation, so that the short circuit risk of the battery cell is reduced, and the use reliability of the battery cell is improved.

In some embodiments, along the first direction, one side of the first insulating member covers the first connection sub-portion, and the other side of the first insulating member covers at least a portion of the active material layer.

By adopting the technical scheme of the embodiment, the first insulating part has wide coverage area and good insulating effect, is favorable for improving the use reliability of the battery cell, can cover the end part of the active material layer, which is close to the transition part, can block burrs of the active material layer, which is close to the transition part, reduce the short circuit risk of the battery cell and improve the use reliability of the battery cell.

In some embodiments, the portion of the first insulating member that overlies the active material layer in the first direction has a dimension H, where 0.2 mm≤H≤1.0 mm, optionally 0.3 mm≤H≤0.8 mm.

By adopting the technical scheme of the embodiment, the part of the first insulating piece covered on the active material layer along the first direction has reasonable size, and the problem of blocking burrs at the end part of the active material layer close to the transition part and the problem of energy density of the battery cell can be simultaneously considered.

In some embodiments, the electrode assembly further includes a second electrode sheet having a polarity opposite to that of the first electrode sheet, the second electrode sheet including a body functional portion and a tab portion arranged in a first direction, an end portion of the body functional portion adjacent to the transition portion having a first end surface from which the tab portion extends outwardly, a side portion of the first connection sub-portion remote from the active material layer in a direction of the conductive portion toward the transition portion without protruding the first end surface, or a projection of the first end surface in a thickness direction of the current collector being located within a projection of the first connection sub-portion.

By adopting the technical scheme of the embodiment, the side part of the first connecting sub-part, which is far away from the active material layer, does not protrude out of the first end surface, so that the first end surface is arranged opposite to the hollowed-out area of the conductive member, the short-circuit risk of the battery cell can be reduced, and the use reliability of the battery cell can be improved. Along the thickness direction of mass flow body, the projection of first terminal surface is located in the projection of first connector portion for the edge that the active material layer was kept away from to first connector portion is not set up with main part functional portion relatively, reducible battery monomer's short circuit risk, is favorable to improving battery monomer's reliability in use.

In some embodiments, the electrode assembly further comprises a second pole piece with polarity opposite to that of the first pole piece, the second pole piece comprises a main body functional part and a pole lug part, the main body functional part is provided with a first end face at the end part close to the transition part, the pole lug part extends outwards from the first end face, and the projection of the first end face is located in the projection of the first insulating part along the thickness direction of the current collector.

By adopting the technical scheme of the embodiment, the first insulating piece can block the tip protrusion at the first end face, so that the short circuit risk of the battery cell is reduced, and the use reliability of the battery cell is improved.

In some embodiments, the number of the metal layers is two, the two metal layers cover opposite sides of the insulating substrate in the thickness direction of the current collector, the number of the active material layers is two, the two active material layers cover conductive portions of the two metal layers respectively, the number of the conductive members is two, first connection portions of the two conductive members are connected with the two metal layers respectively, the number of the first insulators is two, and the two first insulators cover first connection sub-portions of the two conductive members respectively.

Through adopting the technical scheme of this embodiment, the first connecting portion of two electrically conductive members welds with the metal level that is located the relative both sides of insulating base member respectively, can connect the second connecting portion of two electrically conductive members like this to with two metal levels electric conduction, thereby break insulating restriction of insulating base member, can improve the electric conductivity of first pole piece effectively, improve the free quick charge performance of battery, reduce the free risk of generating heat of battery, improve the free reliability in utilization of battery.

In some embodiments, a portion of the first insulating member protruding from the first connection sub-portion forms a blocking portion along a direction in which the conductive portion points toward the transition portion, and the blocking portion is located at a side portion of the second connection portion along a second direction, wherein the second direction is perpendicular to a thickness direction of the current collector in the first direction.

By adopting the technical scheme of the embodiment, the blocking part can block parts such as burrs, metal chips and the like at the edge of the first connecting sub-part far away from the active material layer, so that the short circuit risk of the battery cell is reduced, and the use reliability of the battery cell is improved.

In some embodiments, the blocking portions of the two first insulators are in abutment.

Through adopting the technical scheme of this embodiment, after the blocking portion laminating of two first insulating parts, can keep away from parts parcel such as burr, the metal chip of the edge of active material layer with first connector portion, blocked the burr of the edge of active material layer is kept away from to first connector portion, has reduced the risk of dropping of metal chip, has reduced the free short circuit risk of battery, has improved the free reliability in use of battery.

In some embodiments, the second connection of the two conductive members is soldered and forms a second solder print.

By adopting the technical scheme of the embodiment, the second connecting parts of the two conductive members can be welded to electrically connect the metal layers positioned on two opposite sides of the insulating substrate, so that the insulating limit of the insulating substrate is broken, the conductive capacity of the first pole piece can be effectively improved, the quick charge performance of the battery cell is improved, the heat generation of the battery cell is reduced, and the use reliability of the battery cell is improved.

In some embodiments, the first insulating member overlies at least a portion of the second solder.

By adopting the technical scheme of the embodiment, the first insulating piece can cover the second welding mark, can block the parts such as the tip bulge and the metal scraps on the second welding mark, reduce the short circuit risk of the battery cell and improve the use reliability of the battery cell.

In some embodiments, the first insulating member protrudes beyond the edge of the second solder away from the active material layer in a direction in which the conductive portion points toward the transition portion.

By adopting the technical scheme of the embodiment, the first insulating piece can cover the whole second welding mark, can block parts such as burrs, metal scraps and the like on the second welding mark, reduces the short circuit risk of the battery cell and improves the use reliability of the battery cell.

In some embodiments, the current collector includes a conductive protective layer, at least a portion of which is located between the active material layer and the conductive portion.

Through the technical scheme of this embodiment, the conductive protection layer can separate active material layer and conductive part, plays the guard action to conductive part, reduces the risk such as crackle that leads to conductive part to produce because of the roll-in active material layer, is favorable to improving conductive part's electron transmission ability, has improved battery cell's quick charge performance.

In some embodiments, the conductive protective layer protrudes from the end of the active material layer near the first connection sub-portion in a direction in which the conductive portion points toward the transition portion.

Through the technical scheme of this embodiment, the conductive protection layer can separate active material layer and metal level completely, and the conductive protection layer is better to the protective capability of metal level, and the overcurrent capacity of first pole piece is better, is favorable to improving single battery's quick charge performance and reliability in use.

In some embodiments, the protruding length of the conductive protection layer protruding from the active material layer along the direction in which the conductive portion points to the transition portion ranges from 0.3mm to 0.8mm.

By adopting the technical scheme of the embodiment, the overcurrent capacity and the energy density of the battery monomer can be well considered.

In some embodiments, the first connection portion is welded to a surface of the metal layer facing away from the insulating substrate to form a first solder mark, and the conductive protection layer and the first solder mark are spaced apart along the first direction.

By adopting the technical scheme of the embodiment, the first connecting part can not be welded to the conductive protective layer, so that the risk of cold joint between the first connecting part and the metal layer can be reduced, and the reliability of welding between the first connecting part and the metal layer can be improved.

In some embodiments, the first insulating member is connected to the first pole piece.

By adopting the technical scheme of the embodiment, the first insulating piece is connected to the first pole piece and can be fixed, so that the first connecting part can be stably blocked from parts such as burrs, metal fragments and the like at the edge of the active material layer, and the use reliability of the battery cell can be improved.

In some embodiments, the first insulation member includes an insulation base layer and an adhesive layer, the adhesive layer being adhered between the insulation base layer and the first pole piece.

By adopting the technical scheme of the embodiment, the first insulating part is directly adhered to the first pole piece in the form of an adhesive tape, the risk of leakage coverage is reduced, the insulating base layer and the adhesive layer are covered on the first pole piece to block burrs on the first pole piece, the thickness of the insulating base layer and the thickness of the adhesive layer do not need to be set larger, the energy density of the battery cell is favorably improved, the structural strength of the insulating base layer is good, the burrs on the first pole piece can be stably blocked, the use reliability of the battery cell is improved, the adhesive layer can stably fix the insulating base layer on the first pole piece, the falling risk of the first insulating part is reduced, metal fragments on the first pole piece can be adhered on the adhesive layer, the falling risk of the metal fragments on the first pole piece can be effectively reduced, and the short circuit risk of the battery cell is reduced.

In some embodiments, the insulation base layer has a layer thickness in the range of 6 μm to 15 μm and/or the adhesion layer has a layer thickness in the range of 0.5 μm to 3 μm.

By adopting the technical scheme of the embodiment, the internal insulation and the energy density of the battery cell can be simultaneously considered.

In some embodiments, the first insulator has a dimension W in the first direction, wherein 3 mm≤W≤9 mm, optionally 4.5 mm≤W≤6.5 mm.

By adopting the technical scheme of the embodiment, the insulation reliability and the energy density of the battery cell can be simultaneously considered.

In some embodiments, the thickness of the conductive portion is at least partially less than the thickness of the transition portion.

Through adopting the technical scheme of this embodiment, the thickness of transition portion can be greater than the thickness of conductive part at least part, and the thickness of transition portion is big, has improved the excessive current ability of transition portion, has reduced the heat production of transition portion, reduces first insulating part's melting risk, improves the free use reliability of battery, in addition, also improves the excessive current ability of transition portion, also is favorable to improving the free quick charge performance of battery.

In some embodiments, the conductive portion includes a first sub-portion and a second sub-portion, the first sub-portion being connected between the second sub-portion and the transition portion, the first sub-portion and the second sub-portion being covered with the active material layer, a thickness of the first sub-portion being greater than a thickness of the second sub-portion, and a thickness of the transition portion being greater than or equal to a thickness of the first sub-portion.

By adopting the technical scheme of the embodiment, the thickness of the first sub-part is larger than that of the second sub-part, so that the overcurrent capacity of the first sub-part is larger than that of the second sub-part, the limitation on current can be reduced, the overcurrent capacity of the first pole piece is improved, the heating of the battery cell is reduced, and the use reliability of the battery cell is improved.

In some embodiments, the current collector further comprises a conductive protection layer comprising a first protection portion and a second protection portion, the first protection portion being located between the first sub-portion and the active material layer, the second protection portion being located between the second sub-portion and the active material layer, wherein the thickness of the first protection portion is less than the thickness of the second protection portion.

By adopting the technical scheme of the embodiment, the surface of the conductive protective layer, which is away from the insulating substrate, is close to a plane, which is beneficial to reducing rolling damage and improving the overcurrent capacity of the metal layer, and in addition, the winding bulge problem of the current collector can be reduced.

In some embodiments, the conductive protection layer further includes a third protection portion, the third protection portion covers a surface of the transition portion facing away from the insulating substrate, and a thickness of the third protection portion is less than or equal to a thickness of the first protection portion.

Through the technical scheme of this embodiment, the setting of third protection part can make conductive protection layer protrusion in the active material layer for active material layer and metal layer can separate well, and in addition, the thickness of third protection part is also unlikely to too big, is favorable to reducing the waste of material, saves the cost of manufacture of battery monomer.

In some embodiments, the metal layer further comprises at least one protrusion, the transition portion is connected between the protrusion and the conductive portion, the sum of the dimensions of all the protrusions is smaller than the dimension of the transition portion along a second direction, the second direction is perpendicular to the thickness direction of the current collector, and the thickness of the protrusion is greater than or equal to the thickness of the transition portion.

Through adopting the technical scheme of this embodiment, the thickness of bulge is great, can improve the overflow ability of bulge, is favorable to improving the overflow ability of first pole piece, reduces the free heating of battery, is favorable to improving the free quick charge performance of battery and reliability in use.

In a second aspect, in some embodiments, a battery device includes the battery cells of the above embodiments.

The battery device provided by the embodiment of the application adopts the battery cell, so that the use reliability of the battery cell is good, and the use reliability of the battery device is good.

In a third aspect, in some embodiments, the power device comprises a battery device as in the above embodiments.

The power utilization device provided by the embodiment of the application adopts the battery device, has good use reliability, and is beneficial to improving the use reliability of the power utilization device.

The foregoing description is only an overview of the present application, and is intended to be implemented in accordance with the teachings of the present application in order that the same may be more clearly understood and to make the same and other objects, features and advantages of the present application more readily apparent.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following description will briefly explain the drawings used in the embodiments or the description of the prior art, and it is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a vehicle according to some embodiments of the present application.

Fig. 2 is a schematic structural diagram of a battery device according to some embodiments of the present application.

Fig. 3 is a schematic structural diagram of a battery cell according to some embodiments of the present application.

Fig. 4 is a schematic structural view of an electrode assembly according to some embodiments of the present application.

Fig. 5 is a cross-sectional view taken along line A-A of fig. 4.

Fig. 6 is a schematic structural diagram of a first pole piece, a first insulating member and a second insulating member according to some embodiments of the present application.

Fig. 7 is a sectional view taken along line B-B of fig. 6.

Fig. 8 is a schematic structural diagram of a first pole piece and a second insulating member according to some embodiments of the present application.

Fig. 9 is a partial enlarged view at D in fig. 8.

Fig. 10 is a schematic structural diagram of a first pole piece with a hidden conductive member according to some embodiments of the present application.

Fig. 11 is a partial enlarged view at E in fig. 10.

Fig. 12 is a cross-sectional view taken along line C-C of fig. 6.

Fig. 13 is a cross-sectional view of a first pole piece, a first insulator, and a second insulator along line B-B of fig. 6, as provided by other embodiments of the present application.

Fig. 14 is a schematic structural view of a first insulating member according to some embodiments of the present application.

Fig. 15 is a cross-sectional view taken along line F-F in fig. 14.

Wherein, each reference sign in the figure:

1000. Vehicle, 1100, battery device, 1200, controller, 1300, motor, 100, battery cell, 101, electrode assembly, 1, first electrode tab, 10, current collector, 11, insulating base, 12, metal layer, 121, main body portion, 1211, conductive portion, 12111, first sub portion, 12112, second sub portion, 1212, transition portion, 122, protruding portion, 13, conductive protective layer, 131, first protective portion, 132, second protective portion, 133, third protective portion, 20, active material layer, 30, conductive member, 31, first connecting portion, 311, first connecting sub portion, 312, second connecting sub portion, 32, second connecting portion, 41, first insulator, 4111, insulating base layer, 4112, adhesive layer, 4121, first insulator portion, 4122, second insulator portion, 4131, blocking portion, 42, second insulator portion, 51, first seal, 511, first seal portion, 512, second seal portion, 52, second seal portion, 2, 210, first seal portion, 220, second seal portion, end face, 210, first end face, 210, end face, end cap, 201, end cap, 300, end cap, electrode housing, and case.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects to be solved more clear, the application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs, the terms used herein are for the purpose of describing particular embodiments only and are not intended to be limiting of the application, and the terms "comprising" and "having" and any variations thereof in the description of the application and the claims and the above description of the drawings are intended to cover non-exclusive inclusions.

In the description of embodiments of the present application, the technical terms "first," "second," and the like are used merely to distinguish between different objects and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated, a particular order or a primary or secondary relationship. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least some embodiments of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments in any suitable manner.

In the description of the embodiment of the present application, the term "and/or" is merely an association relationship describing the association object, and indicates that three relationships may exist, for example, a and/or B, and may indicate that a exists alone, while a and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

In the description of the embodiments of the present application, the term "plurality" means two or more (including two), and similarly, "plural sets" means two or more (including two), and "plural sheets" means two or more (including two). The meaning of "a number" is one or more than one unless specifically defined otherwise.

In the description of the embodiments of the present application, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. refer to the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are merely for convenience of describing the embodiments of the present application and for simplifying the description, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the embodiments of the present application.

In describing embodiments of the present application, unless explicitly stated or limited otherwise, the terms "mounted," "connected," "secured" and the like should be construed broadly, and may, for example, be fixedly connected, detachably connected, or integrally formed, mechanically connected, electrically connected, directly connected, indirectly connected through an intervening medium, or in communication between two elements or in an interaction relationship between two elements. The specific meaning of the above terms in the embodiments of the present application will be understood by those of ordinary skill in the art according to specific circumstances.

In the description of embodiments of the application, when an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or be indirectly on the other element unless explicitly stated and limited otherwise. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

The battery cells may include, but are not limited to, lithium ion battery cells, sodium lithium ion battery cells, lithium metal battery cells, sodium metal battery cells, lithium sulfur battery cells, magnesium ion battery cells, nickel hydrogen battery cells, nickel cadmium battery cells, lead storage battery cells, and the like.

As examples, the battery cell may be a cylindrical battery cell, a prismatic battery cell, or other shaped battery cell, including a square-case battery cell, a blade-shaped battery cell, a polygonal-prismatic battery cell, such as a hexagonal-prismatic battery cell, or the like.

The battery device according to the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

In some embodiments, the battery device may be a battery module, and when there are a plurality of battery cells, the plurality of battery cells are arranged and fixed to form one battery module.

In some embodiments, the battery device may be a battery pack including a case and a battery cell, the battery cell or battery module being accommodated in the case.

In some embodiments, the tank may be part of the chassis structure of the vehicle. For example, a portion of the tank may become at least a portion of the floor of the vehicle, or a portion of the tank may become at least a portion of the cross member and the side member of the vehicle.

In some embodiments, the battery device may be an energy storage device. The energy storage device comprises an energy storage container, an energy storage electric cabinet and the like.

The battery cell generally includes an electrode assembly and a case, in which the electrode assembly is received. The electrode assembly includes a positive electrode and a negative electrode. During the charge and discharge of the battery cell, active ions (e.g., lithium ions) are inserted and extracted back and forth between the positive electrode and the negative electrode.

In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode, which may function to prevent the positive electrode and the negative electrode from being shorted, while allowing the active ions to pass through.

The case is used to encapsulate the electrode assembly, the electrolyte, and the like. The shell can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), an aluminum-plastic film or the like.

In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector. The negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector.

The current collector (positive electrode current collector or negative electrode current collector) is usually made of a metal material such as a metal aluminum foil and a metal copper foil. However, the pure metal foil is easy to generate metal burrs, and the burrs penetrate through the diaphragm to cause internal short circuit, so that the battery monomer has larger risk of ignition and explosion.

In order to reduce short circuit risk in a battery cell, a current collector is provided, the current collector comprises an insulating substrate and a metal layer which is covered on the surface of the insulating substrate, an active material layer is covered on the surface of the metal layer, which is opposite to the insulating substrate, the metal layer is smaller in thickness compared with pure metal, burrs generated after cutting the metal layer are smaller, a diaphragm is not easy to pierce, short circuit risk of the battery cell is reduced, a conductive member is usually connected to the edge of the metal layer, the conductive member comprises a first connecting part and a second connecting part which are connected, the first connecting part is connected with the metal layer, the second connecting part is electrically connected with an electrode leading-out part, and therefore electric energy input or output of the battery cell is achieved.

Based on this, the embodiment of the application provides a technical scheme, the conductive member of the battery monomer comprises a first connecting part and at least one second connecting part which are connected, wherein the first connecting part comprises a first connecting sub-part, the first connecting sub-part is covered on the transition part of the main body part of the metal layer, the battery monomer further comprises a first insulating part, the first insulating part is covered on the first connecting sub-part, and along the direction that the conductive part points to the transition part, the first insulating part protrudes out of the edge of the first connecting sub-part away from the active material layer, so that the first insulating part can block burrs at the edge of the first connecting sub-part away from the active material layer, the short circuit risk of the battery monomer is reduced, and the use reliability of the battery monomer is improved.

The battery cell described in the embodiment of the application is suitable for a battery device and an electric device using the battery device.

The battery device disclosed by the embodiment of the application can be used for an electric device using the battery device as a power supply or various energy storage systems using the battery device as an energy storage element. The electric device may be, but is not limited to, a cell phone, a tablet, a notebook computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include fixed or mobile electric toys, such as game machines, electric car toys, electric ship toys, electric plane toys, and the like, and the spacecraft may include planes, rockets, space planes, and spacecraft, and the like.

For convenience of explanation, the following examples will be described taking an electric device as an example of a vehicle.

As shown in fig. 1, the battery device 1100 is provided inside the vehicle 1000, and the battery device 1100 may be provided at the bottom or the head or the tail of the vehicle 1000. The battery device 1100 may be used for power supply of the vehicle 1000, for example, the battery device 1100 may serve as an operating power source of the vehicle 1000.

The vehicle 1000 may also include a controller 1200 and a motor 1300, the controller 1200 being configured to control the battery device 1100 to power the motor 1300, for example, for operating power requirements during start-up, navigation, and travel of the vehicle 1000.

In some embodiments of the present application, the battery device 1100 may not only serve as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, instead of or in part instead of fuel oil or natural gas, to provide driving power for the vehicle 1000. Fig. 2 is an exploded view of a battery device 1100 according to some embodiments of the present application. As shown in fig. 2, the battery device 1100 includes a case 300 and a battery cell accommodated in the case 300.

The case 300 is for receiving the battery cells, and the case 300 may have various structures. In some embodiments, the case 300 may include a first case portion 301 and a second case portion 302, the first case portion 301 and the second case portion 302 being overlapped with each other, the first case portion 301 and the second case portion 302 together defining an accommodating space for accommodating the battery cell. The second case portion 302 may have a hollow structure with one end opened, the first case portion 301 has a plate-like structure, the first case portion 301 is covered on the opening side of the second case portion 302 to form the case 300 having the accommodation space, the first case portion 301 and the second case portion 302 may have hollow structures with one side opened, and the opening side of the first case portion 301 is covered on the opening side of the second case portion 302 to form the case 300 having the accommodation space. Of course, the first and second case portions 301 and 302 may be of various shapes, such as a cylinder, a rectangular parallelepiped, or the like.

In order to improve the sealing property after the first case 301 and the second case 302 are connected, a sealing member, such as a sealant, a gasket, or the like, may be provided between the first case 301 and the second case 302.

Assuming that the first housing portion 301 is covered on top of the second housing portion 302, the first housing portion 301 may also be referred to as an upper case cover, and the second housing portion 302 may also be referred to as a lower housing 300.

In the battery device 1100, the number of battery cells may be one or more. If the number of the battery cells is multiple, the multiple battery cells can be connected in series or in parallel or in series-parallel connection, and the series-parallel connection means that the multiple battery cells are connected in series or in parallel.

The plurality of battery cells can be directly connected in series or parallel or in parallel and then the whole formed by the plurality of battery cells is accommodated in the box 300, or of course, the plurality of battery cells can be connected in series or parallel or in parallel to form a battery module, and the plurality of battery modules are connected in series or parallel or in parallel to form a whole and are accommodated in the box 300.

Illustratively, the battery cell may be the smallest unit that constitutes the battery device 1100.

As shown in fig. 3, in some embodiments, the battery cell includes a case 200 and an electrode assembly 101 accommodated in the case 200. The electrode assembly 101 includes a positive electrode and a negative electrode. During the charge and discharge of the battery cell, active ions (e.g., lithium ions) are inserted and extracted back and forth between the positive electrode and the negative electrode. Optionally, the electrode assembly 101 further includes a separator 3 disposed between the positive electrode and the negative electrode, and the separator 3 may reduce the risk of shorting the positive electrode and the negative electrode while allowing the passage of active ions.

The case 200 is used to encapsulate the electrode assembly 101, electrolyte, and the like.

In some embodiments, the housing 200 includes a shell 202 and an end cap 201, the shell 202 having an opening, the end cap 201 for covering the opening.

The case 202 is a component for cooperating with the end cap 201 to form an internal cavity of the battery cell, which may be used to accommodate the electrode assembly 101, electrolyte, and other components.

The housing 202 and the end cap 201 may be separate components. For example, an opening may be provided in the case 202, and the end cap 201 may be closed at the opening to form an internal cavity of the battery cell.

The housing 202 may be of various shapes and sizes, such as rectangular parallelepiped, cylindrical, hexagonal prism, etc. Specifically, the shape of the case 202 may be determined according to the specific shape and size of the electrode assembly 101. The material of the housing 202 may be various, for example, the material of the housing 202 includes, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, aluminum plastic film, steel plastic film, etc.

The shape of the end cap 201 may be adapted to the shape of the housing 202 to fit the housing 202. The material of the end cap 201 may be the same as or different from the material of the housing 202. Alternatively, the end cap 201 may be made of a material having a certain hardness and strength (such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.), so that the end cap 201 is not easily deformed when being extruded and collided, and thus the battery cell can have a higher structural strength and improved reliability.

The end cap 201 is welded, glued, snapped or otherwise attached to the housing 202.

The housing 202 may be open at one end or open at both ends. In some examples, the housing 202 may be a structure with one side open, and the end cap 201 is provided as one piece and covers the housing 202. In other examples, the housing 202 may have a structure with two openings on two sides, and two end caps 201 are provided, and the two end caps 201 respectively cover the two openings of the housing 202.

In some embodiments, the battery cell includes an electrode lead 2011. The number of the electrode lead-out parts 2011 is two, and the two electrode lead-out parts 2011 are respectively connected with the positive electrode plate and the negative electrode plate for outputting or inputting the electric energy of the battery cell.

In some embodiments, the battery cell further includes an electrolyte contained within the housing 200. The electrolyte serves to conduct ions between the positive and negative electrodes. The electrolyte may be liquid, gel or solid.

In some embodiments, the liquid electrolyte includes an electrolyte salt and a solvent.

In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis-fluorosulfonyl imide, lithium bis-trifluoromethanesulfonyl imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalato borate, lithium difluorodioxaato phosphate, and lithium tetrafluorooxalato phosphate.

In some embodiments, the solvent may include at least one of ethylene carbonate, propylene carbonate, methylethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1, 4-butyrolactone, sulfolane, dimethyl sulfone, methyl sulfone, and diethyl sulfone.

The solvent may also be selected from ether solvents. The ether solvent may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1, 3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether, and crown ether.

In some embodiments, the gel state electrolyte comprises a skeletal network with a polymer as the electrolyte, in combination with an ionic liquid-lithium salt.

In some embodiments, the solid state electrolyte comprises a polymer solid state electrolyte, an inorganic solid state electrolyte, a composite solid state electrolyte.

As examples, the polymer solid electrolyte may be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, single ion polymer, polyion liquid-lithium salt, cellulose, or the like.

As an example, the inorganic solid electrolyte may be one or more of an oxide solid electrolyte (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), a sulfide solid electrolyte (crystalline lithium super ion conductor (lithium germanium phosphorus sulfide, silver sulfur germanium mine), amorphous sulfide), and a halide solid electrolyte, a nitride solid electrolyte, and a hydride solid electrolyte.

As an example, the composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

Referring to fig. 4 and 5, an electrode assembly 101 according to an embodiment of the present application includes first and second electrode sheets 1 and 2 having opposite polarities.

Illustratively, one of the first and second pole pieces 1, 2 is a positive pole piece, and the other is a negative pole piece.

In some embodiments, the positive electrode sheet may include a positive electrode current collector and a positive electrode active material layer disposed on at least one surface of the positive electrode current collector.

As an example, the positive electrode current collector has two surfaces opposing in its own thickness direction, and the positive electrode active material layer is provided on either one or both of the two surfaces opposing the positive electrode current collector.

As an example, the positive electrode current collector may employ carbon, a metal foil, or a composite current collector. For example, stainless steel, copper, aluminum, nickel, carbon electrodes, nickel, titanium, silver-surface-treated aluminum, stainless steel, or the like can be used as the metal foil. The composite current collector may include a polymeric material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel alloy, titanium alloy, silver alloy, etc.) on a polymer material substrate (e.g., a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

As an example, the positive electrode active material layer includes a positive electrode active material, which may include at least one of lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. Other conventional materials that can be used as the positive electrode active material layer of the battery device 1100 can also be used as the positive electrode active material. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium-containing phosphates may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO ₄ (which may also be referred to simply as LFP)), a composite of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO ₄), a composite of lithium manganese phosphate and carbon, lithium manganese iron phosphate, a composite of lithium manganese iron phosphate and carbon. Examples of lithium transition metal oxides may include, but are not limited to, at least one of lithium cobalt oxide (e.g., liCoO ₂), lithium nickel oxide (e.g., liNiO ₂), lithium manganese oxide (e.g., liMnO ₂、LiMn₂O₄), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (e.g., liNi _1/3Co_1/3Mn_1/3O₂ (which may also be abbreviated as NCM 333), liNi _0.5Co_0.2Mn_0.3O₂ (which may also be abbreviated as NCM 523), liNi _0.5Co_0.25Mn_0.25O₂ (which may also be abbreviated as NCM 211), liNi _0.6Co_0.2Mn_0.2O₂ (which may also be abbreviated as NCM 622), liNi _0.8Co_0.1Mn_0.1O₂ (which may also be abbreviated as NCM 811), lithium nickel cobalt aluminum oxide (e.g., liNi _0.80Co_0.15Al_0.05O₂), modified compounds thereof, and the like.

In some embodiments, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material layer disposed on at least one surface of the negative electrode current collector.

As an example, the negative electrode current collector may employ a metal foil, a foam metal, or a composite current collector. For example, as the metal foil, silver-surface-treated aluminum or stainless steel, copper, aluminum, nickel, carbon electrode, nickel or titanium, or the like can be used. The foam metal can be foam nickel, foam copper, foam aluminum, foam alloy, foam carbon or the like. The composite current collector may include a polymeric material base layer and a metal layer. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel alloy, titanium alloy, silver alloy, etc.) on a polymer material substrate (e.g., a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

As an example, the anode active material layer includes an anode active material. The negative electrode active material may employ a negative electrode active material for a battery cell, which is well known in the art. As an example, the anode active material may include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based material, tin-based material, lithium titanate, and the like. The silicon-based material may include at least one of elemental silicon, silicon oxygen compounds, silicon carbon composites, silicon nitrogen composites, and silicon alloys. The tin-based material may include at least one of elemental tin, a tin oxide, and a tin alloy. The anode active material of the present application may also use other conventional materials that can be used as the anode active material of the battery device 1100. These negative electrode active materials may be used alone or in combination of two or more.

In some embodiments, the material of the positive electrode current collector may be aluminum and the material of the negative electrode current collector may be copper.

In some embodiments, the electrode assembly 101 further includes a separator 3, the separator 3 for separating the first and second electrode sheets 1 and 2. The separator 3 can reduce the risk of shorting the positive and negative electrodes while allowing passage of active ions.

In some embodiments, the separator 3 comprises a separator film. The isolating membrane can be any known porous isolating membrane with good chemical stability and mechanical stability.

As an example, the main material of the barrier film may include at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator may be a single-layer film or a multilayer composite film. When the separator is a multilayer composite film, the materials of the respective layers may be the same or different. The separator 3 may be a single member located between the positive and negative electrodes, or may be attached to the surfaces of the positive and negative electrodes.

In some embodiments, the separator 3 is a solid electrolyte. The solid electrolyte is arranged between the positive plate and the negative plate and plays roles in transmitting ions and isolating the positive plate and the negative plate.

In some embodiments, the electrode assembly 101 is a coiled structure. Illustratively, the first pole piece 1 and the second pole piece 2 are each of a ribbon-like structure, and the first pole piece 1, the separator 3, and the second pole piece 2 are wound into a wound structure.

In some embodiments, electrode assembly 101 is a lamination stack.

As an example, a plurality of first pole pieces 1, second pole pieces 2 may be provided, respectively, and a plurality of first pole pieces 1 and a plurality of second pole pieces 2 may be alternately stacked.

As an example, the first pole piece 1 may be provided in plurality, the second pole piece 2 is folded to form a plurality of folded sections which are stacked, and one first pole piece 1 is sandwiched between adjacent folded sections.

As an example, the first pole piece 1 and the second pole piece 2 are each folded to form a plurality of folded sections arranged in a stack.

As an example, the spacers 3 may be provided in plurality, respectively between any adjacent first pole piece 1 or second pole piece 2.

As an example, the separator 3 may be continuously provided, being provided between any adjacent first pole piece 1 or second pole piece 2 by folding or winding.

In some embodiments, the electrode assembly 101 may have a cylindrical shape, a flat shape, a polygonal column shape, or the like.

As shown in fig. 6 to 11, in some embodiments, the battery cell 100 includes a case 200 and an electrode assembly 101, the case 200 is provided with an electrode lead 2011, at least part of the electrode assembly 101 is accommodated in the case 200, the electrode assembly 101 includes a first electrode sheet 1 and a first insulating part 41, the first electrode sheet 1 includes a conductive member 30, a current collector 10 and an active material layer 20, the current collector 10 includes an insulating base 11 and a metal layer 12, the insulating base 11, the metal layer 12 and the active material layer 20 are stacked along a thickness direction of the current collector 10, at least part of the metal layer 12 is located between the insulating base 11 and the active material layer 20, the metal layer 12 includes a main body 121, the main body 121 includes a transition part 1212 and a conductive part 1211 which are arranged and connected along a first direction, the first direction is perpendicular to the thickness direction of the current collector 10, at least part of the conductive part 1211 is covered with the active material layer 20, the transition part 1212 is not covered with the active material layer 20, the conductive member 30 includes a first connecting part 31 and at least one second connecting part 32 connected with the metal layer 12, at least part 31 is connected with the metal layer 12, the second connecting part 1212 and the electrode lead 1212 is connected with the first connecting part 311 is directed away from the first connecting part 311 toward the insulating base 11 along the first connecting surface of the first connecting part 1211.

A part of the electrode assembly 101 is located inside the case 200 and another part is located outside the case 200, or the entire electrode assembly 101 is located inside the case 200.

In some examples, the first electrode sheet 1 is a positive electrode sheet, the current collector 10 is a positive electrode current collector, the positive electrode current collector adopts a composite current collector 10 structure, the active material layer 20 is a positive electrode active material layer 20, or the first electrode sheet 1 is a negative electrode sheet, the current collector 10 is a negative electrode current collector, the negative electrode current collector is a composite current collector 10 structure, and the active material layer 20 is a negative electrode active material layer 20.

The current collector 10 includes a metal layer 12 and an insulating substrate 11, the current collector 10 has a multi-layer structure, the insulating substrate 11 may be a component of the current collector 10 made of an insulating material (for example, the polymer substrate mentioned above), and the metal layer 12 may be a component of the current collector 10 made of the metal material mentioned above.

The surface of the insulating base 11 is covered with the metal layer 12, and the surface of the metal layer 12 facing away from the insulating base 11 is covered with the active material layer 20, so that the insulating base 11, the metal layer 12, and the active material layer 20 are stacked, and the stacking direction of the insulating base 11, the metal layer 12, and the active material layer 20 is the thickness direction of the current collector 10 (refer to the Y direction in fig. 7). The active material layer 20 may be directly coated on the surface of the metal layer 12, or the active material layer 20 may be coated after other materials (for example, the conductive protection layer 13) are coated on the surface of the metal layer 12.

In some examples, one surface of the insulating base 11 is covered with a metal layer 12.

In some examples, the opposite surfaces of the insulating base 11 are both covered with metal layers 12, and of the two metal layers 12, at least one metal layer 12 is covered with an active material layer 20 on a surface facing away from the insulating base 11.

The metal layer 12 includes a body portion 121, and the body portion 121 may refer to a main portion of the metal layer 12.

In some examples, the metal layer 12 may have an equal width structure, and the metal layer 12 is the main body 121.

In some examples, the edges of the metal layer 12 have a protruding structure (e.g., protruding portion 122), and other portions of the metal layer 12 than the protruding structure constitute the body portion 121. Of course, in other examples, other configurations are possible.

In some examples, the body portion 121 is divided into two portions along the first direction, a portion covered with the active material layer 20 is a conductive portion 1211, a portion not covered with the active material layer 20 is a transition portion 1212, and an interface between the conductive portion 1211 and the transition portion 1212 may refer to an end surface of the active material layer 20 near the transition portion 1212 (refer to a broken line G in fig. 7). Wherein the end of the active material layer 20 near the transition portion 1212 may be thinned to reduce the roll pressure experienced by the end of the active material layer 20 near the transition portion 1212 during roll-in of the active material layer 20, thereby reducing damage to the metal layer 12. The end surface of the active material layer 20 near the transition portion 1212 may be a flat surface or may be approximately a straight line.

In some examples, the conductive portion 1211 is an equal-width structure, and the transition portion 1212 may be an equal-width structure with the conductive portion 1211.

The first direction may be a direction perpendicular to the thickness direction of the current collector 10 or a direction nearly perpendicular to the current collector 10, and the second direction may be a direction perpendicular to the thickness direction and the first direction of the current collector 10 or a direction nearly perpendicular to the thickness direction and the first direction of the current collector 10.

In some examples, the electrode assembly 101 is a wound structure, and in the state in which the first electrode sheet 1 is in the expanded state, the first direction may refer to the width direction of the first electrode sheet 1 (refer to the Z direction in fig. 6), and the second direction may refer to the length direction of the first electrode sheet 1 (refer to the X direction in fig. 6). The second direction may also refer to the winding direction of the first pole piece 1 (refer to the direction indicated by arrow V in fig. 4) when the first pole piece 1 is in the wound state.

In some examples, the electrode assembly 101 is a lamination, the first direction may be a width direction of the first electrode sheet 1 (see Z direction in fig. 6), and the second direction may be a length direction of the first electrode sheet 1 (see X direction in fig. 6). The direction of the conductive portion 1211 pointing to the transition portion 1212 may refer to the positive direction in the Z direction in fig. 7, and the direction of the transition portion 1212 pointing to the conductive portion 1211 may refer to the negative direction in the Z direction in fig. 7.

The conductive member 30 may refer to a means for connecting the electrode lead-out portion 2011 and the metal layer 12, and the conductive member 30 may employ copper foil or aluminum foil to improve the overcurrent capability of the conductive member 30.

The electrode lead 2011 may be a metal member for outputting or inputting electric energy, and the electrode lead 2011 may be connected to an external electronic device so that the battery cell 100 outputs or inputs electric energy, and the electrode lead 2011 may be referred to as a post, and the electrode lead 2011 may be provided on the case 202 or the end cap 201.

The conductive member 30 includes a first connection portion 31 and at least one second connection portion 32, the first connection portion 31 may be a portion where the conductive member 30 is connected to the metal layer 12, and the second connection portion 32 may be a portion where the conductive member 30 is connected to the electrode lead 2011. The first connection portion 31 includes a first connection sub-portion 311, and the first connection sub-portion 311 may be a portion of the first connection portion 31 covering a surface of the transition portion 1212 facing away from the insulating base 11, and the first connection sub-portion 311 may cover a portion of the transition portion 1212 or the entire transition portion 1212.

In some examples, the second connection portion 32 may directly extend from the side of the first connection portion 31 facing away from the active material layer 20 along the first direction and facing away from the active material layer 20, so that the second connection portion 32 protrudes out of the insulating base 11, that is, along the thickness direction of the current collector 10, the projection of the first connection portion 31 is located in the projection of the metal layer 12, the projection of the second connection portion 32 is located outside the projection range of the metal layer 12, the projection of the first connection sub-portion 311 is located in the projection range of the transition portion 1212, and the connection positions of the metal layer 12 and the electrode lead-out portion 2011 on the conductive member 30 are different, so that the connection is convenient, and the interaction between the connection of the two may also be reduced, which is beneficial to the connection reliability.

In some examples, the second connection portion 32 and the electrode lead-out portion 2011 may be electrically connected by direct welding, or may be welded by a conductive member (e.g., a switching piece, etc.), and the connection operation is convenient and the processing and manufacturing are convenient. Of course, the electrical connection may also be realized in other ways.

In some examples, when the electrode assembly 101 is formed by winding the electrode plates, the insulating substrate 11 insulates and separates two adjacent layers of the metal layer 12, so that the two adjacent layers of the metal layer 12 are not easy to directly connect across the insulating substrate 11 to transfer current outwards, so that the current can be almost only transferred outwards by the outermost layer of the metal layer 12, the electric conduction capacity is poor, the quick charge performance is low, local overheating is easy to cause, and the use reliability of the battery cell 100 is affected.

In some examples, when the electrode assembly 101 is formed by stacking the electrode sheets, the insulating substrate 11 insulates the two adjacent metal layers 12, which results in that the two adjacent metal layers 12 are not easily connected directly across the insulating substrate 11 to transfer current outwards, so that the current can be almost only transferred outwards by the metal layer 12 located at the outermost side, resulting in poor conductivity, low fast charge performance, and easy local overheating, which affects the reliability of the use of the battery cell 100. In the battery cell 100 of the embodiment of the application, two adjacent metal layers 12 can be electrically conducted by using the second connection portion 32, so that the insulation limit of the insulation substrate 11 is broken, the conductivity of the first pole piece 1 can be effectively improved, the quick charge performance of the battery cell 100 is improved, the heat generation of the battery cell 100 is reduced, and the use reliability of the battery cell 100 is improved.

The first insulating member 41 is made of an insulating material such as PP (polypropylene), PET (polyethylene terephthalate ), or the like. The first insulating member 41 may be, but not limited to, an insulating coating, an insulating adhesive (e.g., a hot melt adhesive), or an insulating tape.

In some examples, the first insulating member 41 may fix the first connection part 311 by means of adhesion or static force absorption, or the like.

In some examples, the first insulating member 41 protrudes from the edge of the first connection sub-portion 311 away from the active material layer 20 in a direction in which the conductive portion 1211 is directed toward the transition portion 1212, and among two sides of the first connection sub-portion 311 that are relatively distributed in the first direction, a side away from the active material layer 20 may be an edge of the first connection sub-portion 311 away from the active material layer 20. Along the thickness direction of the current collector 10, the projection of the first connection sub-portion 311 away from the edge of the active material layer 20 is located within the projection of the first insulating member 41.

In addition, the current collector 10 adopts a composite structure of the insulating substrate 11 and the metal layer 12, and the thickness of the metal layer 12 is small compared with the pure metal current collector 10, so that the burrs generated in the manufacturing process of the current collector 10 are smaller, the internal short circuit risk of the battery cell 100 is reduced, and the use reliability of the battery cell 100 is improved.

In the use process of some battery cells 100, the edge of the first connection part 311 far away from the active material layer 20 may be impacted, so that metal scraps are generated, the metal scraps fall between the first pole piece 1 and the second pole piece 2, the short circuit risk of the battery cells 100 is increased, the use reliability of the battery cells 100 is reduced, and the first insulation member 41 of the battery cells 100 of the embodiment of the application can block the metal scraps, reduce the short circuit risk of the battery cells 100 and improve the use reliability of the battery cells 100.

In some embodiments, referring to fig. 6 and 7, the first insulating member 41 protrudes from the first connection sub-portion 311 near the edge of the active material layer 20 in a direction in which the transition portion 1212 points to the conductive portion 1211.

In some examples, among the two sides of the first connection sub-portion 311 that are relatively distributed in the first direction, a side near the active material layer 20 may refer to an edge of the first connection sub-portion 311 near the active material layer 20. Along the thickness direction of the current collector 10, the projection of the first connection sub-portion 311 near the edge of the active material layer 20 is located within the projection of the first insulating member 41.

In some examples, opposite sides of the first insulating member 41 protrude from opposite edges of the first connection sub-portion 311 in the first direction, respectively, and the projection of the first connection sub-portion 311 is located within the projection of the first insulating member 41 in the thickness direction of the current collector 10, such that the first insulating member 41 may cover the entire first connection sub-portion 311 to insulate the entire first connection sub-portion 311.

By adopting the technical scheme of the embodiment, the first insulating member 41 can cover the edge of the first connecting sub-part 311 close to the active material layer 20, thereby blocking burrs of the edge of the first connecting sub-part 311 close to the active material layer 20, reducing the short circuit risk of the battery cell 100 and improving the use reliability of the battery cell 100, and in addition, the first insulating member 41 can cover the whole first connecting sub-part 311, thereby realizing the whole insulation of the first connecting sub-part 311, effectively reducing the short circuit of the battery cell 100 and improving the use reliability of the battery cell 100.

In some embodiments, referring to fig. 12, in the first direction, an edge of the transition portion 1212 distal from the conductive portion 1211 is flush with an edge of the first connection sub-portion 311 distal from the active material layer 20.

In some examples, of the two sides of the transition portion 1212 that are relatively distributed in the first direction, a side that is away from the conductive portion 1211 may refer to an edge of the transition portion 1212 that is away from the conductive portion 1211.

Along the thickness direction of the current collector 10, the projection of the transition portion 1212 away from the edge of the active material layer 20 coincides with the edge of the first connection sub-portion 311 away from the active material layer 20, so that the side of the first connection sub-portion 311 away from the active material layer 20 is flush with the side of the transition portion 1212 away from the active material layer 20.

In some manufacturing processes of the first pole piece 1, the conductive member 30 is connected to the metal layer 12 of the current collector 10, and the conductive member 30 and the current collector 10 are cut, so that a transition portion 1212 and a first connection sub-portion 311 are obtained, and a side surface of the transition portion 1212 away from the active material layer 20 and a side surface of the first connection sub-portion 311 away from the active material layer 20 are simultaneously cut, so that a side surface of the first connection sub-portion 311 away from the active material layer 20 is flush with a side surface of the transition portion 1212 away from the active material layer 20.

By adopting the technical scheme of the embodiment, along the first direction, the edge of the transition portion 1212 far from the conductive portion 1211 is flush with the edge of the first connection sub-portion 311 far from the active material layer 20, the structure of the first pole piece 1 is regular, the processing and manufacturing are convenient, the redundancy of the first connection sub-portion 311 or the transition portion 1212 can be reduced, the space is saved, the energy density of the battery cell 100 is improved, in addition, the first insulating piece 41 also protrudes out of the edge of the transition portion 1212 far from the active material layer 20, burrs, metal chips and other components at the edge of the transition portion 1212 far from the active material layer 20 are blocked, the short circuit risk of the battery cell 100 is reduced, and the use reliability of the battery cell 100 is improved.

In some embodiments, referring to FIG. 8, conductive portion 1211 has a dimension L ₁ and transition portion 1212 has a dimension L ₂,0.8≤L₂/L₁≤1 along a second direction, wherein the second direction is perpendicular to the first direction and the thickness direction of current collector 10.

0.8.Ltoreq.L ₂/L₁≤1, along the second direction, the size of the transition portion 1212 is smaller than or equal to the size of the conductive portion 1211, and the size of the transition portion 1212 is greater than or equal to 0.8 times or more the size of the conductive portion 1211, so that the size of the transition portion 1212 is not greatly different from or equal to the size of the conductive portion 1211, wherein the larger the size of the transition portion 1212, the larger the connection area of the transition portion 1212 and the first connection sub-portion 311 can be set, and the better the overcurrent capability between the transition portion 1212 and the first connection sub-portion 311.

The value of L ₂/L₁ may be, but is not limited to, 0.8, 1, or any value between 0.8 and 1. Illustratively, the value of L ₂/L₁ may be, but is not limited to, 0.8, 0.85, 0.9, 0.95, 1.

In some examples, 0.8+.L ₂/L₁ <1, in the second direction, the transition 1212 may be located midway between the conductive portions 1211, with both ends of the transition 1212 not being flush with the conductive portions 1211.

In some examples, 0.8+.L ₂/L₁ <1, in the second direction, the transition portion 1212 is disposed with one end that may also be biased toward the conductive portion 1211 such that one end of the transition portion 1212 is flush with the conductive portion 1211, the other end is not flush, or both ends are not flush.

In some examples, L ₂＝L₁, the dimension of the transition portion 1212 is equal to the dimension of the conductive portion 1211 in the second direction, both ends of the transition portion 1212 are flush with the conductive portion 1211, and the transition portion 1212 and the conductive portion 1211 are of equal length.

By adopting the technical scheme of the embodiment, the design of L ₂/L₁ less than or equal to 0.8 less than or equal to 1 ensures that the dimension of the transition portion 1212 along the second direction is large, which is beneficial to improving the connection area between the first connection sub-portion 311 and the transition portion 1212, improving the overcurrent capacity of the first pole piece 1, reducing the heat generation of the battery cell 100 and improving the quick charge performance of the battery cell 100.

In some embodiments, referring to fig. 7 to 9, the first connection portion 31 is welded to the surface of the metal layer 12 facing away from the insulating substrate 11 to form a first solder mark 51, and along the first direction, the first solder mark 51 is located on a side of the active material layer 20 near the transition portion 1212.

The first connecting portion 31 is welded to the side portion of the metal layer 12, which is located near the transition portion 1212, of the active material layer 20, and the welding formed by the welding is a first welding 51, and the first welding 51 may be a whole welding or may be formed by combining multiple welding. The first connector portion 311 may or may not be welded to the transition portion 1212.

By adopting the technical scheme of the embodiment, the first connecting part 31 is welded on the metal layer 12, the welding operation is simple, the manufacture and the processing of the first pole piece 1 are convenient, the first welding mark 51 is positioned on one side of the active material layer 20 close to the transition part 1212, so that the first welding mark 51 is spaced from the active material layer 20, the virtual welding risk of the first connecting part 31 and the metal layer 12 caused by the active material layer 20 is reduced, and the use reliability of the battery cell 100 is improved.

In some embodiments, referring to fig. 7, the first insulator 41 covers at least a portion of the first solder print 51.

The first insulating member 41 may cover a portion of the first solder mark 51, or may cover the entire first solder mark 51.

By adopting the technical solution of this embodiment, the first insulating member 41 can block the burrs, metal chips and other components on the first solder mark 51, reduce the risk of short circuit of the battery cell 100, and improve the reliability of use of the battery cell 100.

In some embodiments, referring to fig. 7 to 9, the first solder mark 51 includes a first solder mark portion 511, and the first connection sub-portion 311 is soldered to a surface of the transition portion 1212 facing away from the insulating substrate 11 and forms the first solder mark portion 511.

The first connection sub-portion 311 is welded to the surface of the transition portion 1212 facing away from the insulating substrate 11, and the welding is performed as a first welding portion 511.

By adopting the technical scheme of the embodiment, the first connecting sub-portion 311 is welded with the transition portion 1212, so that current can directly flow to the conductive member 30 through the transition portion 1212, which is beneficial to improving the overcurrent capacity of the first pole piece 1 and improving the quick charge performance of the battery cell 100.

In some embodiments, referring to FIG. 8, the transition 1212 has a dimension L ₂ and the first solder 511 has a dimension L ₃,0.8≤L₃/L₂ 1. Ltoreq.1 in a second direction, which is perpendicular to the first direction and the thickness direction of the current collector 10.

Along the second direction, the dimension L ₃ of the first solder portion 511 may be less than or equal to the dimension L ₂ of the transition portion 1212, the dimension L ₃ of the first solder portion 511 is greater than or equal to 0.8 times the dimension L ₂ of the transition portion 1212, the dimension L ₃ of the first solder portion 511 exceeds more than half the dimension L ₂ of the transition portion 1212, and the longer the dimension L ₃ of the first solder portion 511, the larger the welding area of the transition portion 1212 and the first connection sub-portion 311, and the better the overcurrent capability at the connection of the transition portion 1212 and the first connection sub-portion 311.

In some examples, 0.8+.L ₃/L₂ <1, in the second direction, the first solder portion 511 may be located midway along the transition portion 1212, with opposite edges of the first solder portion 511 not being flush with opposite sides of the transition portion 1212.

In some examples, 0.8+.L ₃/L₂ <1, in the second direction, the first solder portion 511 is disposed with one end that may also be biased toward the transition portion 1212 such that one edge of the first solder portion 511 is flush with one side of the transition portion 1212 and the other edge of the first solder portion 511 is not flush with the other side of the transition portion 1212.

In some examples, L ₃＝L₂, in the second direction, a dimension L ₃ of the first solder portion 511 is equal to a dimension L ₂ of the transition portion 1212, and opposite edges of the first solder portion 511 are flush with opposite sides of the transition portion 1212.

The value of L ₃/L₂ may be, but is not limited to, 0.8, 1, or any value between 0.8 and 1. Illustratively, the value of L ₃/L₂ may be, but is not limited to, 0.8, 0.85, 0.9, 0.95, 1.

By adopting the technical scheme of the embodiment, the design of L ₃/L₂ less than or equal to 0.8 less than or equal to 1 ensures that the size of the first welding part 511 along the second direction is larger, which is beneficial to improving the connection area between the first connection sub-part 311 and the transition part 1212, improving the overcurrent capacity of the connection part of the first connection sub-part 311 and the transition part 1212, improving the overcurrent capacity of the first pole piece 1, reducing the heat generation of the battery cell 100 and improving the quick charge performance of the battery cell 100.

In some embodiments, referring to fig. 7, the first insulator 41 covers at least a portion of the first solder print 511.

In some examples, the first insulating member 41 covers a portion of the first welded portion 511, and, illustratively, a projection of the first insulating member 41 coincides with a projection portion of the first welded portion 511 in a thickness direction of the current collector 10.

In some examples, the first insulator 41 covers the entire first welded portion 511, and, illustratively, the projection of the first welded portion 511 in the thickness direction of the current collector 10 falls within the projection range of the first insulator 41.

By adopting the technical solution of this embodiment, the first insulating member 41 can block the burrs, metal chips and other components on the first welding portion 511, reduce the risk of short-circuiting of the battery cell 100, and improve the reliability of use of the battery cell 100.

In some embodiments, referring to fig. 6-9, the first insulating member 41 protrudes from the edge of the first solder 511 near the active material layer 20 along the direction of the transition portion 1212 pointing to the conductive portion 1211, and/or the first insulating member 41 protrudes from the edge of the first solder 511 far from the active material layer 20 along the direction of the conductive portion 1211 pointing to the transition portion 1212.

Among the two edges of the first solder portion 511 that are relatively distributed in the first direction, the edge near the active material layer 20 is the edge of the first solder portion 511 near the active material layer 20, and the edge far from the active material layer 20 is the edge of the first solder portion 511 active material layer 20.

In some examples, the first insulating member 41 protrudes from the first solder 511 near the edge of the active material layer 20 in a direction in which the transition 1212 points toward the conductive portion 1211.

Along the thickness direction of the current collector 10, the projection of the first welding part 511 near the edge of the active material layer 20 is positioned in the projection of the first insulating member 41, the first insulating member 41 covers the edge of the first welding part 511 near the active material layer 20, and the first insulating member 41 can block burrs, metal scraps and other components of the edge of the first welding part 511 near the active material layer 20, so that the short circuit risk of the battery cell 100 is reduced, and the use reliability of the battery cell 100 is improved.

In some examples, the first insulating member 41 protrudes from the edge of the first solder 511 away from the active material layer 20 in a direction in which the conductive portion 1211 points toward the transition portion 1212.

Along the thickness direction of the current collector 10, the projection of the edge of the first welding part 511 away from the active material layer 20 is positioned in the projection of the first insulating member 41, the first insulating member 41 covers the edge of the first welding part 511 away from the active material layer 20, and the first insulating member 41 can block burrs, metal scraps and other components at the edge of the first welding part 511 away from the active material layer 20, so that the short circuit risk of the battery cell 100 is reduced, and the use reliability of the battery cell 100 is improved.

For example, the first insulating member 41 covers the first solder portion 511, and the first insulating member 41 may extend from the first solder portion 511 away from the active material layer 20 until protruding the edge of the first connection sub-portion 311 away from the active material layer 20, such that the first insulating member 41 covers the edge of the first connection sub-portion 311 away from the active material layer 20.

In some examples, the first insulating member 41 protrudes the first solder 511 near the edge of the active material layer 20 in a direction in which the transition portion 1212 points to the conductive portion 1211, and the first insulating member 41 protrudes the first solder 511 away from the edge of the active material layer 20 in a direction in which the conductive portion 1211 points to the transition portion 1212.

For example, along the thickness direction of the current collector 10, the projection of the first welding portion 511 is located in the first insulating member 41, the first insulating member 41 covers the entire first welding portion 511, and the first insulating member 41 may also cover the entire first welding portion 511, thereby blocking burrs, metal chips, and the like on the entire first welding portion 511, thereby effectively reducing the risk of short-circuiting of the battery cell 100 and improving the reliability of use of the battery cell 100.

By adopting the technical solution of this embodiment, the first insulating member 41 can cover the edges of the first solder print portions 511 that are relatively distributed along the first direction, and can block burrs, metal chips, and other components at the edges of the first solder print portions 511 that are relatively distributed along the first direction, thereby effectively reducing the risk of short-circuiting of the battery cell 100 and improving the reliability of use of the battery cell 100.

In some embodiments, referring to fig. 8 and 9, in the first direction, an edge of the first solder portion 511 away from the active material layer 20 is flush with an edge of the first connection sub-portion 311 away from the active material layer 20.

In some examples, the projection of the first welded portion 511 away from the edge of the active material layer 20 coincides with the edge of the first connection sub-portion 311 away from the active material layer 20 in the thickness direction of the current collector 10, and the side of the first connection sub-portion 311 away from the active material layer 20 may be made flush with the edge of the first welded portion 511 away from the active material layer 20.

In some manufacturing processes of the first electrode sheet 1, the conductive member 30 is welded to the metal layer 12 of the current collector 10 and forms an equal width weld extending along the second direction, and in a cutting process of the first electrode sheet 1, the equal width weld may be cut along the second direction, so as to obtain the first connection part 311 and the first weld part 511, and the equal width weld is cut along the second direction, so that the edge of the first weld part 511 away from the active material layer 20 and the side of the first connection part 311 away from the active material layer 20 are cut simultaneously, so that the side of the first connection part 311 away from the active material layer 20 is flush with the edge of the first weld part 511 away from the active material layer 20. The edge of the first solder portion 511 away from the active material layer 20 is cut, so that a larger burr may be generated at the edge of the first solder portion 511 away from the active material layer 20, and the short-circuit risk of the battery cell 100 is increased, while the first insulator 41 protrudes out of the edge of the first connector portion 311 away from the active material layer 20, so that the first insulator 41 also protrudes out of the edge of the first solder portion 511 away from the active material layer 20, and the first insulator 41 can cover the edge of the first solder portion 511 away from the active material layer 20, thereby blocking the burr at the edge of the first solder portion 511 away from the active material layer 20, reducing the short-circuit risk of the battery cell 100, and improving the reliability of the battery cell 100.

By adopting the technical scheme of the embodiment, along the first direction, the edge of the first welding part 511 away from the active material layer 20 is flush with the edge of the first connecting sub part 311 away from the active material layer 20, the first pole piece 1 has a regular structure, the processing and manufacturing of the first pole piece 1 can be facilitated, the redundancy of the first connecting sub part 311 can be reduced, the space is saved, the energy density of the battery cell 100 is improved, in addition, the first insulating part 41 also protrudes from the edge of the first welding part 511 away from the active material layer 20, the first insulating part 41 can cover the edge of the first welding part 511 away from the active material layer 20, so that burrs at the edge of the first welding part 511 away from the active material layer 20 can be blocked, the short circuit risk of the battery cell 100 is reduced, and the use reliability of the battery cell 100 is improved.

In some embodiments, referring to fig. 8 and 9, along the second direction, opposite edges of the transition portion 1212 are respectively flush with opposite edges of the first connection sub-portion 311, and opposite edges of the first solder portion 511 are respectively flush with opposite edges of the first connection sub-portion 311.

In some examples, two sides of the transition portion 1212 that are relatively distributed along the second direction may refer to two opposite edges of the transition portion 1212 that are relatively distributed along the second direction, two sides of the first connection sub-portion 311 that are relatively distributed along the second direction may refer to two opposite edges of the first connection sub-portion 311 that are relatively distributed along the second direction, and among the two sides of the transition portion 1212 that are relatively distributed along the second direction, the first solder portion 511 extends from one side to the other side of the transition portion 1212, wherein the first solder portion 511 may extend straight along the second direction, may extend obliquely or arcuately with respect to the second direction, etc., and in the second direction, the size of the first solder portion 511, the size of the transition portion 1212, and the size of the first connection sub-portion 311 are equal.

In some examples, along the thickness direction of the current collector 10, projections of opposite edges of the transition portion 1212 along the second direction, projections of opposite edges of the first connection sub-portion 311 along the second direction, and projections of opposite edges of the first solder portion 511 along the second direction coincide.

In some first pole piece 1 manufacturing processes, the pole piece sheet has welding marks continuously arranged along the second direction, and is cut at intervals along the second direction, so as to obtain a plurality of first pole pieces 1, and along the second direction, two opposite edges of the transition portion 1212 and two opposite edges of the first connection sub-portion 311 are cut, so that two opposite edges of the transition portion 1212 are respectively flush with two opposite edges of the first connection sub-portion 311 along the second direction, and the welding marks continuously arranged along the second direction are also cut into a plurality of first welding mark portions 511, so that two opposite edges of the first welding mark portions 511 are respectively flush with two opposite edges of the first connection sub-portion 311 along the second direction.

By adopting the technical scheme of the embodiment, the two side surfaces of the first pole piece 1 which are distributed oppositely along the second direction have regular structures, so that the processing and manufacturing of the first pole piece 1 can be facilitated, the redundancy of the first connecting sub-part 311 and the transition part 1212 can be reduced, the space can be saved, the energy density of the battery cell 100 can be improved, in addition, the size of the first welding part 511 along the second direction is equal to the size of the transition part 1212, the welding area between the transition part 1212 and the first connecting sub-part 311 can be increased, the overcurrent capacity of the first pole piece 1 can be improved, and the quick-charging performance of the battery cell 100 can be improved.

In some embodiments, referring to fig. 7 to 11, the metal layer 12 further includes at least one protruding portion 122, the transition portion 1212 is connected between the protruding portion 122 and the conductive portion 1211, the sum of the dimensions of all protruding portions 122 is smaller than the dimension of the transition portion 1212 along a second direction perpendicular to the thickness direction of the current collector 10, the first connection portion 31 includes at least one second connection sub-portion 312, the second connection sub-portion 312 is connected between the first connection sub-portion 311 and the second connection portion 32, the second connection sub-portion 312 covers the surface of the protruding portion 122 facing away from the insulating substrate 11, and the second connection sub-portion 312 corresponds to the protruding portion 122 one by one.

In the first direction, the protruding portion 122 may refer to a protruding structure of an edge portion of the main body portion 121, that is, the protruding portion 122 may be obtained by extending from a side surface of the transition portion 1212 away from the conductive portion 1211 outward in the first direction, the protruding portion 122 is not covered with the active material layer 20, a portion of the first connection portion 31 covering the protruding portion 122 forms a second connection sub-portion 312, that is, the first connection portion 31 is divided into two portions in the first direction, where the portion covering the protruding portion 122 is the second connection sub-portion 312, and the portion covering the transition portion 1212 is the first connection sub-portion 311. The second connection sub-portion 312 is connected between the first connection sub-portion 311 and the second connection portion 32, and the interface between the first connection sub-portion 311 and the second connection sub-portion 312 can refer to the side of the transition portion 1212 away from the active material layer 20 (see the dotted line N in fig. 12), i.e. the side of the transition portion 1212 leading out of the protrusion 122, and the interface between the second connection sub-portion 312 and the second connection portion 32 can refer to the side of the protrusion 122 facing away from the transition portion 1212 (see the dotted line M in fig. 7).

In some examples, the number of the protruding portions 122 is 1, the protruding portions 122 and the transition portion 1212 form a step structure, L ₂＞l₁, the number of the protruding portions 122 is a plurality of protruding portions 122 protruding from the same side of the transition portion 1212, the protruding portions 122 are arranged at intervals along the second direction, the protruding portions 122 have the same structure, and L ₂＞N*l₁.

In addition, the protruding part 122 can be connected with the second connecting sub-part 312, thereby increasing the connection area between the metal layer 12 and the first connecting part 31, improving the overcurrent capacity between the metal layer 12 and the first connecting part 31 and improving the quick charge performance of the battery cell 100.

In some embodiments, referring to fig. 7 to 11, the first solder mark 51 includes at least one second solder mark portion 512, and the second connector portion 312 is soldered with the corresponding protruding portion 122 and forms a second solder mark portion 512.

The second connector portion 312 is welded to the surface of the corresponding protruding portion 122 facing away from the insulating substrate 11, and the welding mark formed by the welding is the second welding mark portion 512. The second connection sub-portions 312 are disposed in one-to-one correspondence with the second solder portions 512.

In some examples, the first weld 51 may include only the second weld 512, i.e., the second connector sub-portion 312 is welded with the protrusion 122, and the first connector sub-portion 311 is not welded with the transition portion 1212.

In some examples, the first solder mark 51 may include a first solder mark portion 511 and a second solder mark portion 512, that is, the first connection sub-portion 311 is welded with the transition portion 1212, and the second connection sub-portion 312 is welded with the protrusion portion 122, which increases the welding area of the first connection portion 31 and the metal layer 12, and is beneficial to improving the overcurrent capability between the first connection portion 31 and the metal layer 12 and improving the quick charge capability of the battery cell 100.

In some examples, the first and second solder portions 511 and 512 may form a single solder, for example, the single solder may be cut from the same width solder as described above, and the boundary between the first and second solder portions 511 and 512 may be referred to as the side of the second connector portion 312 away from the active material layer 20.

In some examples, the first solder portion 511 and the second solder portion 512 may also be separate two solder marks.

By adopting the technical solution of this embodiment, the second connection sub-portion 312 is welded with the protruding portion 122, and the connection of the first connection portion 31 with the metal layer 12 can be achieved.

Of course, in other examples, the first solder 51 may include only the first solder portion 511, i.e., the first connector portion 311 is soldered to the transition portion 1212, and the second connector portion 312 is not soldered to the protrusion 122.

In some embodiments, referring to fig. 6 to 9, the first insulating member 41 covers at least a portion of the second solder portion 512.

In some examples, the first insulating member 41 covers a portion of the second solder portion 512, and, illustratively, a projection of the first insulating member 41 coincides with a projection portion of the second solder portion 512 in a thickness direction of the current collector 10.

In some examples, the first insulator 41 covers the entire second weld 512, and, illustratively, the projection of the second weld 512 falls within the projection range of the first insulator 41 in the thickness direction of the current collector 10.

By adopting the technical solution of this embodiment, the first insulating member 41 can block the burrs, metal chips and other components on the second welding portion 512, reduce the risk of short circuit of the battery cell 100, and improve the reliability of use of the battery cell 100.

In some embodiments, referring to fig. 6-9, the first insulating member 41 protrudes from the second solder portion 512 near the edge of the active material layer 20 along the direction in which the transition portion 1212 points to the conductive portion 1211, and/or the first insulating member 41 protrudes from the edge of the second solder portion 512 away from the active material layer 20 along the direction in which the conductive portion 1211 points to the transition portion 1212.

Of the two edges of the second solder portion 512 that are distributed relatively along the first direction, the edge near the active material layer 20 is the edge of the second solder portion 512 near the active material layer 20, and the edge far from the active material layer 20 is the edge of the active material layer 20 of the second solder portion 512.

In some examples, the first and second solder portions 511 and 512 form a monolithic solder, and an edge of the second solder portion 512 near the active material layer 20 coincides with an edge of the first solder portion 511 away from the active material layer 20, i.e., an edge of the second solder portion 512 near the active material layer 20 and an edge of the first solder portion 511 away from the active material layer 20 may refer to a boundary line of the first and second solder portions 511 and 512.

In some examples, the first insulating member 41 protrudes from the second solder portion 512 near the edge of the active material layer 20 in a direction in which the transition portion 1212 points toward the conductive portion 1211.

Along the thickness direction of the current collector 10, the projection of the second welding part 512 near the edge of the active material layer 20 is located in the projection of the first insulating member 41, the first insulating member 41 covers the edge of the second welding part 512 near the active material layer 20, the first insulating member 41 can block burrs, metal scraps and other components of the second welding part 512 near the edge of the active material layer 20, the short circuit risk of the battery cell 100 is reduced, and the use reliability of the battery cell 100 is improved.

For example, the first insulating member 41 covers the first connection sub-portion 311, and the first insulating member 41 may extend from the first connection sub-portion 311 away from the active material layer 20 to the second solder portion 512, such that the first insulating member 41 covers an edge of the second solder portion 512 near the active material layer 20.

In some examples, the first insulating member 41 protrudes the second solder portion 512 away from the edge of the active material layer 20 in a direction in which the conductive portion 1211 points toward the transition portion 1212.

Along the thickness direction of the current collector 10, the projection of the edge of the second welding part 512 away from the active material layer 20 is located in the projection of the first insulating member 41, the first insulating member 41 covers the edge of the second welding part 512 away from the active material layer 20, and the first insulating member 41 can block burrs, metal scraps and other components at the edge of the second welding part 512 away from the active material layer 20, so that the short circuit risk of the battery cell 100 is reduced, and the use reliability of the battery cell 100 is improved.

For example, the first insulating member 41 covers the first connection sub-portion 311, and the first insulating member 41 may extend from the first connection sub-portion 311 away from the active material layer 20 to the second solder portion 512 and out of the second solder portion 512, such that the first insulating member 41 covers an edge of the second solder portion 512 away from the active material layer 20.

In some examples, the first insulating member 41 protrudes the second solder portion 512 near the edge of the active material layer 20 in a direction in which the transition portion 1212 points to the conductive portion 1211, and the first insulating member 41 protrudes the second solder portion 512 away from the edge of the active material layer 20 in a direction in which the conductive portion 1211 points to the transition portion 1212.

For example, along the thickness direction of the current collector 10, the projection of the second welding portion 512 is located in the first insulating member 41, the first insulating member 41 covers the entire second welding portion 512, and the first insulating member 41 may also cover the entire second welding portion 512, thereby blocking burrs, metal chips and other components on the entire second welding portion 512, thereby effectively reducing the risk of short-circuiting of the battery cell 100 and improving the reliability of use of the battery cell 100.

By adopting the technical solution of this embodiment, the first insulating member 41 can cover the edges of the second solder printing portion 512 that are relatively distributed along the first direction, and can block burrs, metal chips, and other components at the edges of the second solder printing portion 512 that are relatively distributed along the first direction, thereby effectively reducing the risk of short-circuiting of the battery cell 100 and improving the reliability of use of the battery cell 100.

In some embodiments, referring to fig. 6-9, the first insulating member 41 protrudes from the edge of the second connection sub-portion 312 near the active material layer 20 along the direction in which the transition portion 1212 points to the conductive portion 1211, and/or the first insulating member 41 protrudes from the edge of the second connection sub-portion 312 far from the active material layer 20 along the direction in which the conductive portion 1211 points to the transition portion 1212.

Of the two side surfaces of the second connection sub-portion 312 that are distributed relatively in the first direction, the side surface near the active material layer 20 is the edge of the second connection sub-portion 312 near the active material layer 20, and the side surface far from the active material layer 20 is the edge of the active material layer 20 of the second connection sub-portion 312.

In some examples, the first connection sub-portion 311, the second connection sub-portion 312, and the second connection sub-portion 32 are an integrated structure, a side of the second connection sub-portion 312 near the active material layer 20 coincides with a side of the first connection sub-portion 311 far from the active material layer 20, a side of the second connection sub-portion 312 near the active material layer 20 and a side of the first connection sub-portion 311 far from the active material layer 20 may refer to an interface between the first connection sub-portion 311 and the second connection sub-portion 312, a side of the second connection sub-portion 32 near the active material layer 20 coincides with a side of the second connection sub-portion 312 far from the active material layer 20, and a side of the second connection sub-portion 32 near the active material layer 20 and a side of the second connection sub-portion 312 far from the active material layer 20 may refer to an interface between the second connection sub-portion 32 and the second connection sub-portion 312.

In some examples, the first insulating member 41 protrudes from the second connector sub-portion 312 near the edge of the active material layer 20 in a direction in which the transition portion 1212 points toward the conductive portion 1211.

Along the thickness direction of the current collector 10, the projection of the second connector 312 near the edge of the active material layer 20 is located in the projection of the first insulator 41, the first insulator 41 covers the edge of the second connector 312 near the active material layer 20, and the first insulator 41 can block burrs, metal chips and other components of the second connector 312 near the edge of the active material layer 20, so that the short circuit risk of the battery cell 100 is reduced, and the use reliability of the battery cell 100 is improved.

For example, the first insulating member 41 covers the first connection sub-portion 311, and the first insulating member 41 may extend from the first connection sub-portion 311 to the second connection sub-portion 312 away from the active material layer 20, such that the first insulating member 41 covers the second connection sub-portion 312 near the edge of the active material layer 20.

In some examples, the first insulating member 41 protrudes the second connector sub-portion 312 away from the edge of the active material layer 20 in a direction in which the conductive portion 1211 points toward the transition portion 1212.

Along the thickness direction of the current collector 10, the projection of the edge of the second connector 312 away from the active material layer 20 is located in the projection of the first insulating member 41, the first insulating member 41 covers the edge of the second connector 312 away from the active material layer 20, and the first insulating member 41 can block burrs, metal chips and other components at the edge of the second connector 312 away from the active material layer 20, so that the short circuit risk of the battery cell 100 is reduced, and the use reliability of the battery cell 100 is improved.

For example, the first insulating member 41 covers the first connection sub-portion 311, and the first insulating member 41 may extend from the first connection sub-portion 311 away from the active material layer 20 to the second connection sub-portion 312 and out of the second connection sub-portion 312, such that the first insulating member 41 covers an edge of the second connection sub-portion 312 away from the active material layer 20.

In some examples, the first insulating member 41 protrudes the second connector portion 312 near the edge of the active material layer 20 in a direction in which the transition portion 1212 points toward the conductive portion 1211, and the first insulating member 41 protrudes the second connector portion 312 away from the edge of the active material layer 20 in a direction in which the conductive portion 1211 points toward the transition portion 1212.

For example, along the thickness direction of the current collector 10, the projection of the second connector portion 312 is located in the first insulating member 41, the first insulating member 41 covers the entire second connector portion 312, and the first insulating member 41 may also cover the entire second connector portion 312, thereby blocking burrs, metal chips, and other components on the entire second connector portion 312, thereby effectively reducing the risk of short-circuiting of the battery cell 100 and improving the reliability of use of the battery cell 100.

By adopting the technical solution of this embodiment, the first insulating member 41 can cover the edges of the second connector portion 312 that are relatively distributed along the first direction, and can block the burrs, metal chips, and other components at the edges of the second connector portion 312 that are relatively distributed along the first direction, thereby effectively reducing the risk of short-circuiting of the battery cell 100 and improving the reliability of use of the battery cell 100.

In some embodiments, referring to fig. 6 to 9, the first insulating member 41 includes a first insulating portion 4121 and at least one second insulating portion 4122, the first insulating portion 4121 covers the first connector portion 311, the second insulating portion 4122 covers the second connector portion 312, and the second insulating portion 4122 corresponds to the second connector portion 312 one by one.

In some examples, the portion of the first insulating member 41 covering the first connection sub-portion 311 is a first insulating portion 4121, the portion of the first insulating member 41 covering the second connection sub-portion 312 is a second insulating portion 4122, the first insulating portion 4121 and the second insulating portion 4122 are arranged along the first direction, the first insulating portion 4121 is closer to the active material layer 20 than the second insulating portion 4122, wherein the number of the second insulating portions 4122 is the same as the number of the second connection sub-portions 312, and the second insulating portions 4122 are covered on the second connection sub-portion 312 in a one-to-one correspondence. The interface between the first insulating portion 4121 and the second insulating portion 4122 may refer to the side of the second connector portion 312 away from the active material layer 20 (refer to the dashed line N in fig. 12).

By adopting the technical scheme of the embodiment, the first insulating member 41 can cover the first connecting sub-portion 311 and the second connecting sub-portion 312, so that the coverage area of the first insulating member 41 is increased, the insulating effect of the first insulating member 41 is improved, the short circuit risk of the battery cell 100 is reduced, and the use reliability of the battery cell 100 is improved.

In some embodiments, referring to fig. 6, at least one of the opposite sides of the first insulating portion 4121 protrudes from the corresponding side of the first connection sub-portion 311 along the second direction.

Of the two side portions of the first insulating portion 4121 that are distributed opposite in the second direction, one side portion protrudes from the side surface of the first connecting sub portion 311 that is on the same side as the side portion, and the other side portion protrudes or does not protrude from the other side surface of the first connecting sub portion 311.

In some manufacturing processes of the first pole piece 1, burrs may be generated on the side surfaces of the first connecting sub-portions 311 along the second direction after the pole piece sheet is cut, so that the battery cell 100 may be shorted, and particularly, large burrs may be generated on the side surfaces of the first connecting sub-portions 311 along the second direction due to the second welding portions 512 obtained through cutting, so that the risk of shorting the battery cell 100 is increased.

By adopting the technical solution of this embodiment, the first insulating portion 4121 can block burrs at the side of the first connector portion 311 along the second direction, so that the risk of short circuit of the battery cell 100 can be reduced, and the reliability of use of the battery cell 100 can be improved.

In some embodiments, as shown in fig. 6 to 9, the number of the protruding portions 122 is plural, the number of the second connection sub-portions 312 is plural, the plurality of protruding portions 122 are arranged at intervals along the second direction, the plurality of second connection sub-portions 312 are arranged at intervals along the second direction, the plurality of protruding portions 122 and the plurality of second connection sub-portions 312 are arranged in a one-to-one correspondence, the number of the second connection portions 32 is plural, the plurality of second connection portions 32 are arranged at intervals along the second direction, the second connection sub-portions 312 are connected with the second connection portions 32 in a one-to-one correspondence, the plurality of second connection sub-portions 312 are connected to the edge of the first connection sub-portion 311 facing away from the active material layer 20, the first connection sub-portions 311 are arranged continuously along the second direction, the number of the second insulation portions 4122 is plural, the plurality of second insulation portions 4122 are arranged along the second direction, and the second insulation portions 4122 are in a one-to-one correspondence with the second connection sub-portions 312.

In some examples, the number of the protruding portions 122 is plural, the protruding portions 122 are disposed at intervals along the second direction, each protruding portion 122 is correspondingly covered with one second connection sub-portion 312, each second connection sub-portion 312 is correspondingly connected with one second connection portion 32, the second connection portions 32 are disposed at intervals along the second direction, and each second connection sub-portion 312 is correspondingly covered with one second insulation portion 4122. After the pole piece is wound, the plurality of protruding portions 122 may be stacked together so that the plurality of second connecting portions 32 are also stacked together to facilitate electrical connection with the electrode lead-out portion 2011.

By adopting the technical scheme of the embodiment, the first connecting sub-part 311 is continuously arranged along the second direction, a plurality of second connecting sub-parts 312 can be connected into a whole, the first connecting sub-part 311 can play a good supporting role on the second connecting sub-part 312, the risk of inserting the second connecting sub-part 312 between the first pole piece 1 and the second pole piece 2 when bending can be reduced, the short circuit risk of the battery cell 100 is reduced, the use reliability of the battery cell 100 is improved, the size of the first connecting sub-part 311 is large along the second direction, the improvement of the welding area between the first connecting sub-part 311 and the transition part 1212 is facilitated, the improvement of the overcurrent capacity between the first connecting part 31 and the transition part 1212 is facilitated, the overcurrent capacity of the first pole piece 1 is improved, the quick charging performance and the use reliability of the battery cell 100 are improved, the plurality of the protruding parts 122 are arranged at intervals along the second direction, the main body part is facilitated to be divided into a plurality of areas along the second direction, one area can correspond to one protruding part 122, electrons in each area can be correspondingly led out of the corresponding electrode 2011 to the corresponding to the short circuit region 121, the whole transmission path of the battery cell can be reduced, the electronic transmission performance of the whole is facilitated, and the short circuit can be reduced, the whole transmission path of the electronic transmission path can be reduced, and the electronic transmission path can be increased to the whole is facilitated, and the electronic transmission path can be increased, and the whole can be easily and the electronic transmission path can be reduced.

In some embodiments, referring to fig. 6, two adjacent second insulating portions 4122 meet.

In some examples, adjacent two second insulating portions 4122 are connected to each other at the side portions close to each other, thereby forming one body.

In some examples, the first insulating member 41 extends in the second direction and has an equal width structure, the first insulating member 41 is divided into two portions in the first direction, wherein a portion close to the active material layer 20 is a first insulating portion 4121, a portion far from the active material layer 20 may be divided into a plurality of second insulating portions 4122 in the second direction, and the plurality of second insulating portions 4122 are sequentially connected in the second direction and form a unitary structure.

By adopting the technical scheme of the embodiment, two adjacent second insulating parts 4122 can be directly connected to form an integral structure, so that the installation of the first insulating part 41 can be facilitated, meanwhile, the second insulating parts 4122 can also cover two opposite edges of the second connecting sub-part 312 along the second direction, the parts such as the tip protrusions and the metal fragments at two opposite side surfaces of the second connecting sub-part 312 along the second direction are blocked, the short circuit risk of the battery cell 100 is improved, and the use reliability of the battery cell 100 is improved.

In some embodiments, referring to fig. 8 and 9, the first solder marks 51 are spaced apart from the active material layer 20 in a first direction.

The projection of the first solder mark 51 does not coincide with the projection of the active material layer 20 in the thickness direction of the current collector 10.

In some examples, the first electrode sheet 1 is a positive electrode sheet, a gap exists between the first solder mark 51 and the active material layer 20, and the gap can be used to provide a space between the first connector portion 311 and the active material layer 20, so as to reduce risks of lithium precipitation and the like of the first electrode sheet 1 caused by contact between the first connector portion 311 and the active material layer 20, and in addition, a space can be provided for the sides, close to the active material layer 20, of the first solder mark 51 and the first connector portion 311, so that the first solder mark 51 cannot extend to the side, close to the active material layer 20, of the first connector portion 311, and the risk of being welded through or cracked and the like at the side, close to the active material layer 20, of the first connector portion 311 is reduced, burrs, metal fragments and the like generated by welding are reduced, and use reliability of the battery cell 100 is improved.

In some examples, the first electrode sheet 1 is a negative electrode sheet, a gap exists between the first welding mark 51 and the active material layer 20, and a space can be provided for the first welding mark 51 and the side surface, close to the active material layer 20, of the first connecting sub-portion 311, so that the first welding mark 51 cannot extend to the side surface, close to the active material layer 20, of the first connecting sub-portion 311, and risks of welding through or welding crack and the like at the side surface, close to the active material layer 20, of the first connecting sub-portion 311 are reduced, burrs, metal fragments and other components generated by welding are reduced, and use reliability of the battery cell 100 is improved, wherein the first connecting sub-portion 311 can be connected with the active material layer 20, and can also be arranged at intervals.

By adopting the technical scheme of the embodiment, a gap exists between the first welding mark 51 and the active material layer 20, so that the welding of the first connecting portion 31 and the metal layer 12 cannot be welded to the active material layer 20, the risk of cold joint between the first connecting portion 31 and the metal layer 12 is reduced, and the use reliability of the battery cell 100 is improved.

In some embodiments, referring to FIGS. 8 and 9, the first solder print 51 is spaced from the active material layer 20 by S ₁ in a first direction, where 0.3mm < S ₁ < 5mm.

In some examples, the first solder 51 includes only the first solder 511, and s ₁ is the distance between the first solder 511 and the active material layer 20.

In some examples, the first bond 51 includes only the second bond 512, and s ₁ is the spacing of the second bond 512 from the active material layer 20.

In some examples, the first solder 51 includes a first solder 511 and a second solder 512, s ₁ being the spacing of the first solder 511 from the active material layer 20.

The design that S ₁ is more than or equal to 0.3mm enables the first welding mark 51 and the active material layer 20 to have a distance, the first connecting portion 31 cannot be welded to the active material layer 20, the virtual welding risk of the first connecting portion 31 and the metal layer 12 is reduced, and the design that S ₁ is less than or equal to 5mm enables the distance between the first welding mark 51 and the active material layer 20 not to be too large, and therefore the coverage area of the active material layer 20 on the metal layer 12 is improved, and the energy density of the battery cell 100 is improved.

The value of S ₁ can be 0.3mm, 5mm, and any value between 0.3mm and 5mm, for example, the value of S ₁ can be, but is not limited to, 0.3mm, 0.5mm, 1mm, 2mm, 2.5mm, 2.8mm, 3mm, 4mm, 5mm.

By adopting the technical scheme of the embodiment, the design that S ₁ is smaller than or equal to 0.3mm and smaller than or equal to 5mm ensures that the first welding mark 51 is not welded on the active material layer 20, reduces the false welding risk of the first connecting part 31 and the metal layer 12, is beneficial to improving the connection reliability of the first connecting part 31 and the metal layer 12 and the use reliability of the battery cell 100, and in addition, the distance between the active material layer 20 and the first welding mark 51 is reasonable, the distance between the active material layer 20 and the first welding mark 51 is relatively close, so that under the condition that the dimension of the metal layer 12 in the first direction is certain, the coverage area of the active material layer 20 is more, and the energy density of the battery cell 100 is beneficial to improvement.

In some embodiments, 0.5 mm≤S ₁≤2.8 mm.

By adopting the technical scheme of the embodiment, the distance between the active material layer 20 and the first welding mark 51 is more reasonable due to the design that S ₁ is less than or equal to 0.5mm and less than or equal to 2.8mm, and the connection reliability of the first connection part 31 and the energy density of the battery cell 100 can be better considered.

In some embodiments, referring to fig. 7 to 9, the electrode assembly 101 includes a second insulating member 42, where the second insulating member 42 covers a surface of the metal layer 12 facing away from the insulating substrate 11, and the entire second insulating member 42 is located between the first solder mark 51 and the active material layer 20.

The second insulating member 42 may refer to a member made of an insulating material, such as PP (polypropylene), PET (polyethylene terephthalate ), or the like. The second insulator 42 may be, but is not limited to, an insulating coating, an insulating adhesive (e.g., hot melt adhesive), or an insulating tape.

The second insulator 42 covers the portion of the metal layer 12 between the first solder 51 and the active material layer 20.

In some examples, a portion of the second insulator 42 may be located between the first connection sub-portion 311 and the metal layer 12, another portion of the second insulator 42 may be located between the first connection sub-portion 311 and the active material layer 20, or the entire second insulator 42 may be located between the first connection sub-portion 311 and the active material layer 20.

By adopting the technical solution of this embodiment, the second insulating member 42 covers the portion of the metal layer 12 between the first solder mark 51 and the active material layer 20, so that insulation of this portion can be achieved, which is beneficial to reducing the risk of short circuit of the battery cell 100 and improving the reliability of use of the battery cell 100.

In some embodiments, referring to fig. 12, the first connection sub-portion 311 is spaced apart from the active material layer 20 along the first direction.

The projection of the first connection sub-portion 311 does not overlap with the projection of the active material layer 20 in the thickness direction of the current collector 10.

By adopting the technical solution of this embodiment, the first connector portion 311 is not in contact with the active material layer 20, so that the interaction between the two is reduced, which is beneficial to improving the performance of the battery cell 100.

In some embodiments, at least a portion of the second insulator 42 is located between the first connector portion 311 and the active material layer 20.

In some examples, a portion of the second insulator 42 is located within the spacing space formed by the first connection sub-portion 311 and the active material layer 20, and another portion of the second insulator 42 is located between the first connection sub-portion 311 and the metal layer 12.

In some examples, the entire second insulating member 42 is located in the space formed by the first connection sub-portion 311 and the active material layer 20, and the second insulating member 42 does not extend between the first connection sub-portion 311 and the metal layer 12, which is advantageous in that the first solder mark 51 and the second insulating member 42 are spaced apart, and the risk of cold soldering of the first connection portion 31 and the metal layer 12 is reduced.

In some battery cells 100, the second connection portion 32 is bent and then connected with the electrode lead-out portion 2011, and the transition portion 1212 is bent along with the second connection portion 32 in the process of bending, so that the portion of the transition portion 1212 between the first connection portion 311 and the active material layer 20 may have a crack or other problem, while the second insulation member 42 covers the portion of the transition portion 1212 between the first connection portion 311 and the active material layer 20, and the second insulation member 42 can support the portion, thereby reducing the risk of cracking, and in addition, the second insulation member 42 covers the portion of the transition portion 1212 between the first connection portion 311 and the active material layer 20, thereby realizing insulation of the portion, reducing the risk of short circuit of the battery cell 100, and improving the reliability of use of the battery cell 100.

In some embodiments, referring to fig. 5-7, the electrode assembly 101 further includes a second electrode sheet 2 having a polarity opposite to that of the first electrode sheet 1, the second electrode sheet 2 includes a main body functional portion 210 and an electrode ear portion 220 arranged along a first direction, an end portion of the main body functional portion 210 near the transition portion 1212 has a first end face 2101, the electrode ear portion 220 extends outward from the first end face 2101, and a projection of the first end face 2101 is located within a projection of the second insulating member 42 along a thickness direction of the current collector 10.

The main body functional portion 210 may refer to a main body structure of the second pole piece 2, the tab portion 220 may refer to a protruding structure extending from an end of the main body functional portion 210 near the transition portion 1212, the tab portion 220 is electrically connected to the electrode lead-out portion 2011, and the conductive member 30 and the tab portion 220 are electrically connected to the electrode lead-out portions 2011 with different polarities, so as to implement charge and discharge of the battery cell 100.

Of the two end surfaces of the main body function portion 210 that are relatively distributed in the first direction, one end surface near the transition portion 1212 forms a first end surface 2101.

By adopting the technical scheme of the embodiment, the first end face 2101 is opposite to the second insulating piece 42, and the second insulating piece 42 can block burrs at the first end face 2101, so that the short circuit risk of the battery cell 100 is reduced, and the use reliability of the battery cell 100 is improved.

In some embodiments, referring to fig. 7, in the first direction, one side of the first insulating member 41 covers the first connection sub-portion 311, and the other side of the first insulating member 41 covers at least a portion of the second insulating member 42.

Along the thickness direction of the current collector 10, the projection of the first insulating member 41 coincides with the projection portion of the second insulating member 42.

The first insulating member 41 may cover a part of the second insulating member 42, or may cover the entire second insulating member 42.

In some examples, the first insulating member 41 may be fixed to the second insulating member 42 by adhesion or static attraction, although in other examples, the first insulating member 41 may be fixed to the second insulating member 42 in other manners.

By adopting the technical scheme of the embodiment, the first insulating member 41 and the second insulating member 42 can realize double-layer insulation, reduce the risk of short circuit of the battery cell 100, and improve the use reliability of the battery cell 100.

In some embodiments, referring to fig. 13, in the first direction, one side of the first insulating member 41 covers the first connection sub-portion 311, and the other side of the first insulating member 41 covers at least a portion of the active material layer 20.

It can be understood that, of the two side portions of the first insulating member 41 that are distributed oppositely along the first direction, one side portion covers the first connection sub-portion 311, and the other side portion covers at least a partial area of the active material layer 20, where the first insulating member 41 may cover an end portion of the active material layer 20 facing the first connection sub-portion 311, or may cover the entire active material layer 20.

In some examples, the first insulating member 41 may extend from the active material layer 20 to the first connection sub-portion 311 and extend out of the first connection sub-portion 311 in the first direction such that a portion of the metal layer 12 between the first connection sub-portion 311 and the active material layer 20 is covered with the first insulating member 41, and insulation of this portion may be achieved. The portion of the metal layer 12 between the first connection sub-portion 311 and the active material layer 20 may be covered with the second insulating member 42, or may not be covered with the second insulating member 42.

In some examples, a portion of the metal layer 12 between the first connection sub-portion 311 and the active material layer 20 may be covered with the second insulating member 42, and the first insulating member 41 may entirely cover the second insulating member 42.

In some examples, the portion of the metal layer 12 between the first connection sub-portion 311 and the active material layer 20 may not be covered with the second insulating member 42, and the first insulating member 41 may cover the portion of the metal layer 12 between the first connection sub-portion 311 and the active material layer 20, thereby achieving insulation of the portion, which is beneficial to improving the reliability of use of the battery cell 100, and in addition, the second insulating member 42 may be omitted, so that the cost is saved, and at the same time, the active material layer 20 may be used to cover the original position of the second insulating member 42, so that the coverage area of the active material layer 20 on the metal layer 12 may be increased, which is beneficial to improving the energy density of the battery cell 100.

By adopting the technical scheme of the embodiment, the first insulating part 41 has wide coverage area and good insulating effect, is favorable for improving the use reliability of the battery cell 100, and can cover the end part of the active material layer 20, which is close to the transition part 1212, of the first insulating part 41, can block burrs of the active material layer 20, which are close to the transition part 1212, reduce the short circuit risk of the battery cell 100 and improve the use reliability of the battery cell 100.

In some embodiments, referring to FIG. 13, in the first direction, the portion of the first insulating member 41 that covers the active material layer 20 has a dimension H, where 0.2 mm≤H≤1.0 mm.

The design that H is more than or equal to 0.2mm enables the first insulating part 41 to cover the end part of the active material layer 20, which is close to the transition part 1212, and the first insulating part 41 can block burrs at the end part of the active material layer 20, which is close to the transition part 1212, so that the use reliability of the battery cell 100 is improved, and the design that H is less than or equal to 1.0mm enables the part of the first insulating part 41, which covers the active material layer 20, not to be too large, is beneficial to reducing the weight and the volume of the first insulating part 41 and is beneficial to improving the energy density of the battery cell 100.

In some examples, the value of H may be 0.2mm, 1mm, or any value between 0.2 mm-1.0 mm, and illustratively, the value of H may be, but is not limited to, 0.2mm, 0.3mm, 0.4mm, 0.6mm, 0.8mm, 0.9mm, 1mm.

By adopting the technical solution of this embodiment, the portion of the first insulating member 41 covering the active material layer 20 along the first direction is reasonable in size, and both the burrs at the end portion of the active material layer 20 near the transition portion 1212 and the energy density of the battery cell 100 can be simultaneously prevented.

In some embodiments, 0.3 mm≤H≤0.8 mm.

By adopting the technical solution of this embodiment, the dimension of the portion of the first insulating member 41 covering the active material layer 20 in the first direction is more reasonable, and the problem of blocking burrs at the end portion of the active material layer 20 near the transition portion 1212 and the problem of energy density of the battery cell 100 can be better considered.

In some embodiments, referring to fig. 5 and 12, the electrode assembly 101 further includes a second electrode sheet 2 having a polarity opposite to that of the first electrode sheet 1, the second electrode sheet 2 includes a body functional portion 210 and a tab portion 220 arranged in a first direction, an end portion of the body functional portion 210 adjacent to the transition portion 1212 has a first end face 2101, the tab portion 220 extends outwardly from the first end face 2101, and a side portion of the first connection sub-portion 311 remote from the active material layer 20 does not protrude from the first end face 2101 in a direction of the conductive portion 1211 toward the transition portion 1212.

Along the thickness direction of the current collector 10, the projection of the side surface of the first connection sub-portion 311 away from the active material layer 20 falls within the projection range of the main body functional portion 210, so that the first end surface 2101 and the hollow region of the conductive member 30, from which the second connection portion 32 or the second connection sub-portion 312 does not extend, are disposed opposite to each other.

By adopting the technical scheme of the embodiment, the first end face 2101 is arranged opposite to the hollowed-out area of the conductive member 30, so that the short circuit risk of the battery cell 100 can be reduced, and the use reliability of the battery cell 100 can be improved.

In some embodiments, referring to fig. 5 and 12, the projection of the first end face 2101 is located within the projection of the first connection sub-portion 311 in the thickness direction of the current collector 10.

Along the direction of the conductive portion 1211 toward the transition portion 1212, the side portion of the first connection sub-portion 311 away from the active material layer 20 protrudes out of the first end face 2101, so that the edge of the first connection sub-portion 311 away from the active material layer 20 is not opposite to the main body functional portion 210, which can reduce the risk of short circuit of the battery cell 100 and is beneficial to improving the reliability of use of the battery cell 100.

In some embodiments, referring to fig. 5 and 7, the electrode assembly 101 further includes a second electrode sheet 2 having a polarity opposite to that of the first electrode sheet 1, the second electrode sheet 2 includes a body function portion 210 and a tab portion 220 arranged along a first direction, an end portion of the body function portion 210 adjacent to the transition portion 1212 has a first end face 2101, the tab portion 220 extends outwardly from the first end face 2101, and a projection of the first end face 2101 is located within a projection of the first insulating member 41 along a thickness direction of the current collector 10.

In some examples, the first insulating member 41 includes a first insulating portion 4121 and a second insulating portion 4122, the projection of the first end face 2101 is located within the projection of the first insulating portion 4121 along the thickness direction of the current collector 10, the first end face 2101 is disposed opposite to the first connection sub-portion 311 along the direction in which the conductive portion 1211 is directed toward the transition portion 1212, the main body function portion 210 does not protrude the edge of the first connection sub-portion 311 away from the active material layer 20, or the projection of the first end face 2101 is located within the projection of the second insulating portion 4122, the first end face 2101 is located opposite to the second insulating portion 4122 along the direction in which the conductive portion 1211 is directed toward the transition portion 1212, and the main body function portion 210 protrudes the edge of the first connection sub-portion 311 away from the active material layer 20.

By adopting the technical solution of this embodiment, the first insulating member 41 can block the tip protrusion at the first end face 2101, reducing the risk of short circuit of the battery cell 100, and improving the reliability of use of the battery cell 100.

In some embodiments, referring to fig. 7, the number of metal layers 12 is two, the number of the two metal layers 12 covers opposite sides of the insulating base 11 in the thickness direction of the current collector 10, the number of the active material layers 20 is two, the two active material layers 20 respectively cover the conductive portions 1211 of the two metal layers 12, the number of the conductive members 30 is two, the first connection portions 31 of the two conductive members 30 are respectively connected to the two metal layers 12, the number of the first insulators 41 is two, and the two first insulators 41 respectively cover the first connection sub-portions 311 of the two conductive members 30.

The number of the metal layers 12, the number of the first insulating pieces 41, the number of the active material layers 20 and the number of the conductive members 30 are two, the two metal layers 12 are respectively covered on two opposite sides of the insulating base 11 in the thickness direction, the two active material layers 20 are respectively covered on the conductive portions 1211 of the two metal layers 12, the first connecting portion 31 of one conductive member 30 is connected to the surface of one metal layer 12 facing away from the insulating base 11, the first connecting portion 31 of the other conductive member 30 is connected to the surface of the other metal layer 12 facing away from the insulating base 11, and the two first insulating pieces 41 are positioned on two opposite sides of the insulating base 11 in the thickness direction and are respectively covered on the first connecting sub-portions 311 of the two conductive members 30.

By adopting the technical scheme of the embodiment, the first connecting parts 31 of the two conductive members 30 are respectively welded with the metal layers 12 positioned on two opposite sides of the insulating substrate 11, so that the second connecting parts 32 of the two conductive members 30 can be connected, and the two metal layers 12 are electrically conducted, thereby breaking the insulation limit of the insulating substrate 11, effectively improving the conductivity of the first pole piece 1, improving the quick charge performance of the battery cell 100, reducing the heating risk of the battery cell 100, and improving the use reliability of the battery cell 100.

In some embodiments, referring to fig. 6, the portion of the first insulating member 41 protruding from the first connection sub-portion 311 along the direction in which the conductive portion 1211 points to the transition portion 1212 forms a blocking portion 4131, and the blocking portion 4131 is located at a side portion of the second connection portion 32 along a second direction perpendicular to the first direction and the thickness direction of the current collector 10.

The blocking portion 4131 may refer to a portion of the first insulating member 41 protruding from an edge of the first connection sub-portion 311 away from the active material layer 20, and the blocking portion 4131 is located at one of two sides of the second connection portion 32 that are oppositely distributed in the second direction.

In some examples, the blocking portion 4131 may refer to a portion of the first insulating member 41 located outside of the projection of the metal layer 12 in the thickness direction of the current collector 10.

In some examples, the first insulating member 41 includes a first insulating portion 4121 and a second insulating portion 4122, and portions of adjacent two first insulating portions 4121 corresponding to regions of the first connector portion 311 from which the second connector portion 312 is not drawn form a blocking portion 4131. In the manufacturing or using process of the battery cell 100, the area where the first connector portion 311 is not led out of the second connector portion 312 may generate burrs, metal chips and other components, so that the short circuit risk of the battery cell 100 is increased, and the blocking portion 4131 can block the burrs, the metal chips and other components in the areas, so that the short circuit risk of the battery cell 100 is reduced, and the use reliability of the battery cell 100 is improved.

By adopting the technical solution of this embodiment, the blocking portion 4131 can block the burrs, metal chips, and other components at the edge of the first connection sub-portion 311 away from the active material layer 20, thereby reducing the risk of short-circuiting of the battery cell 100 and improving the reliability of use of the battery cell 100.

In some embodiments, referring to fig. 12, the blocking portions 4131 of the two first insulating members 41 are attached.

Along the thickness direction of the current collector 10, the two first insulators 41 are located at opposite sides of the first pole piece 1, and the blocking portions 4131 of the two first insulators 41 are staggered from the second connection sub-portions 312 and the second connection portions 32 of the conductive members 30, so that the blocking portions 4131 of the two first insulators 41 can be directly attached, wherein the blocking portions 4131 of the two first insulators 41 can be attached by, but not limited to, bonding or static adsorption.

Through adopting the technical scheme of this embodiment, after the blocking portion 4131 of two first insulating pieces 41 is laminated, can keep away from parts such as burr, the metal piece of active material layer 20's edge department with first connector portion 311 parcel, blockked the burr of active material layer 20's edge department is kept away from to first connector portion 311, reduced the risk of dropping of metal piece, reduced the short circuit risk of battery monomer 100, improved the reliability in use of battery monomer 100.

In some embodiments, referring to fig. 7, the second connection portions 32 of the two conductive members 30 are soldered and form a second solder mark 52.

In some examples, the portion of the conductive member 30 protruding from the side of the protrusion 122 away from the active material layer 20 along the direction of the conductive portion 1211 toward the transition portion 1212 forms the second connection portion 32, so that the second connection portions 32 of the two conductive members 30 can be directly relatively close to each other to be welded together, and the trace of the welding is the second weld mark 52. The second connection portions 32 of the two conductive members 30 may be welded by ultrasonic welding, laser welding, or the like.

By adopting the technical scheme of the embodiment, the second connecting parts 32 of the two conductive members 30 can be welded to electrically connect the metal layers 12 positioned on two opposite sides of the insulating substrate 11, so that the insulation limit of the insulating substrate 11 is broken, the conductivity of the first pole piece 1 can be effectively improved, the quick charge performance of the battery cell 100 is improved, the heat generation of the battery cell 100 is reduced, and the use reliability of the battery cell 100 is improved.

In some embodiments, referring to fig. 7, the first insulating member 41 covers at least a portion of the second solder print 52.

The first insulating member 41 may cover a portion of the second solder 52, and the first insulating member 41 may cover the entire second solder 52.

By adopting the technical scheme of the embodiment, the first insulating member 41 can cover the second solder mark 52, and can block the tip protrusion, metal scraps and other parts on the second solder mark 52, so that the short circuit risk of the battery cell 100 is reduced, and the use reliability of the battery cell 100 is improved.

In some embodiments, referring to fig. 7, the first insulating member 41 protrudes from the edge of the second solder 52 away from the active material layer 20 along the direction in which the conductive portion 1211 points to the transition portion 1212.

Of the two edges of the second solder mark 52 that are distributed relatively in the first direction, the edge that is far from the active material layer 20 is the edge of the second solder mark 52 that is far from the active material layer 20.

In some examples, the first insulating member 41 may extend from the first connection sub-portion 311 to the second connection portion 32 facing away from the active material layer 20 and protrude beyond the edge of the second solder 52 facing away from the active material layer 20 in a direction in which the conductive portion 1211 points toward the transition portion 1212, i.e., in a thickness direction of the current collector 10, a projection of the second solder 52 falls within a projection of the first insulating member 41 such that the first insulating member 41 can cover the entire second solder 52.

By adopting the technical scheme of the embodiment, the first insulating member 41 can cover the whole second welding mark 52, and can block burrs, metal chips and other parts on the second welding mark 52, so that the short circuit risk of the battery cell 100 is reduced, and the use reliability of the battery cell 100 is improved.

In some embodiments, referring to fig. 7, current collector 10 includes a conductive protective layer 13, at least a portion of conductive protective layer 13 being located between active material layer 20 and conductive portion 1211.

In some examples, the conductive protection layer 13 may refer to a layer of conductive structure provided between the active material layer 20 and the conductive portion 1211, the conductive structure being capable of conducting electricity so that electrons can be transferred between the active material layer 20 and the conductive portion 1211, enabling the input or output of electric energy from the battery cell 100. The conductive protection layer 13 may have an equal thickness structure or a different thickness structure.

Illustratively, a portion of the conductive protective layer 13 is located between the active material layer 20 and the conductive portion 1211, and another portion covers the transition portion 1212 and protrudes beyond the active material layer 20.

Illustratively, the entire conductive protective layer 13 is located between the active material layer 20 and the conductive portion 1211.

In some examples, the conductive protection layer 13 may contain conductive carbon black and a binder, which on one hand plays a role in buffering and lubrication between the active material layer 20 and the conductive portion 1211, and can relieve damage to the metal layer 12 caused by particles in the active material layer 20 during rolling of the first electrode sheet 1, and on the other hand, the conductive carbon black can reduce contact resistance between the particles in the active material layer 20 and the conductive portion 1211, which is beneficial to improving the service performance of the battery cell 100.

In the rolling process of the first pole piece 1, the thickness of the metal layer 12 is thinner, particles in the active material layer 20 can damage the metal layer 12, so that the conductive part 1211 is easy to crack and the like, but the conductive protective layer 13 in the embodiment of the application can separate the active material layer 20 and the conductive part 1211, has a protective effect on the conductive part 1211, reduces risks such as cracks and the like generated by the conductive part 1211 due to rolling of the active material layer 20, is beneficial to improving the electron transmission capability of the conductive part 1211, and improves the quick charge performance of the battery cell 100.

In some embodiments, referring to fig. 7, the conductive protection layer 13 protrudes from the end of the active material layer 20 near the first connection sub-portion 311 in a direction in which the conductive portion 1211 points to the transition portion 1212.

In some examples, a part of the conductive protection layer 13 covers the conductive portion 1211, another part covers the transition portion 1212, the conductive protection layer 13 protrudes from the active material layer 20, the conductive protection layer 13 can completely separate the metal layer 12 and the active material layer 20, and an epitaxial space can be provided for the rolling process of the active material layer 20, so that the risk of direct contact between the active material layer 20 and the metal layer 12 is reduced.

By adopting the technical scheme of the embodiment, the conductive protection layer 13 can completely separate the active material layer 20 and the metal layer 12, the protection capability of the conductive protection layer 13 on the metal layer 12 is better, the overcurrent capability of the first pole piece 1 is better, and the quick charge performance and the use reliability of the battery cell 100 are improved.

In some embodiments, referring to fig. 7, the protruding length of the conductive protection layer 13 protruding from the active material layer 20 along the direction of the conductive portion 1211 pointing to the transition portion 1212 ranges from 0.3mm to 0.8mm.

The protruding distance of the conductive protection layer 13 protruding from the active material layer 20 is S ₂, wherein the value of 0.3mm +.s ₂≤0.8mm,S₂ may be 0.3mm, 0.8mm, or any value between 0.3mm and 0.8mm, for example, the value of S ₂ may be, but not limited to, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm.

The design that S ₂ is more than or equal to 0.3mm can enable the conductive protection layer 13 to completely separate the active material layer 20 from the metal layer 12, the protection capability of the conductive protection layer 13 on the metal layer 12 is good, the overcurrent capability of the first pole piece 1 is better, the quick charge performance and the use reliability of the battery cell 100 are improved, and the design that S ₂ is less than or equal to 0.8mm enables the conductive protection layer 13 not to protrude out of the active material layer 20 too much, occupies more space, is beneficial to saving the internal space of the battery cell 100 and improves the energy density of the battery cell 100.

By adopting the technical scheme of the embodiment, the overcurrent capacity and the energy density of the battery cell 100 can be well considered.

In some embodiments, the first connection portion 31 is welded to the surface of the metal layer 12 facing away from the insulating substrate 11 to form a first solder mark 51, and the conductive protection layer 13 and the first solder mark 51 are spaced apart along the first direction.

In some examples, the conductive protection layer 13 is disposed at a distance from the first connection sub-portion 311, and the second insulating portion 4122 covers a portion of the conductive protection layer 13 between the first connection sub-portion 311 and the active material layer 20.

By adopting the technical solution of this embodiment, the first connection portion 31 is not welded to the conductive protection layer 13, so that the risk of cold joint between the first connection portion 31 and the metal layer 12 can be reduced, which is beneficial to improving the reliability of welding between the first connection portion 31 and the metal layer 12.

In some embodiments, referring to fig. 7, a first insulator 41 is connected to the first pole piece 1.

In some examples, the first insulating member 41 may be connected to the transition portion 1212, the conductive member 30, and the active material layer 20, wherein the first insulating member 41 may be connected to the first pole piece 1 by bonding or static adsorption.

By adopting the technical scheme of the embodiment, the first insulating member 41 is connected to the first pole piece 1, and the first insulating member 41 can be fixed, so that the first connecting sub-portion 311 can be stably blocked from burrs, metal chips and other components at the edge away from the active material layer 20, which is beneficial to improving the use reliability of the battery cell 100.

In some embodiments, referring to fig. 7, 14 and 15, the first insulating member 41 includes an insulation base layer 4111 and an adhesive layer 4112, the adhesive layer 4112 being adhered between the insulation base layer 4111 and the first pole piece 1.

The first insulating member 41 is in the form of an adhesive tape, the insulating base layer 4111 may refer to the main body 121 of the first insulating member 41, the adhesive layer 4112 may refer to an adhesive covering the surface of the insulating base layer 4111, and the material of the insulating base layer 4111 may be polyethylene terephthalate, polypropylene, or the like. The material of the adhesive layer 4112 may be acrylic, rubber, latex, or the like. The structure of the first insulating member 41 may be the same as or different from that of the second insulating member 42.

In some battery cells 100, insulating glue (e.g., hot melt glue, etc.) may be applied to the first solder marks 51 to form the first insulating member 41, but the coating operation may risk missing the coating, and in addition, the insulating glue needs to be applied thicker to cover burrs, metal chips, etc. on the first solder marks 51, which is not beneficial to improving the volumetric energy density of the battery cells 100.

By adopting the technical scheme of the embodiment, the first insulating piece 41 is in the structure form of an adhesive tape, the first insulating piece 41 can be directly adhered to the first pole piece 1, the risk of leakage coverage is reduced, the insulating base layer 4111 and the bonding layer 4112 are covered on the first pole piece 1, burrs on the first pole piece 1 are prevented, the thickness of the insulating base layer 4111 and the thickness of the bonding layer 4112 do not need to be set larger, the energy density of the battery cell 100 is favorably improved, the structural strength of the insulating base layer 4111 is good, burrs on the first pole piece 1 can be stably prevented, the use reliability of the battery cell 100 is improved, the bonding layer 4112 can stably fix the insulating base layer 4111 on the first pole piece 1, the risk of falling of the first insulating piece 41 is reduced, metal scraps on the first pole piece 1 can be bonded on the bonding layer 4112, the risk of falling of metal scraps on the first pole piece 1 is effectively reduced, and the risk of short circuit of the battery cell 100 is reduced.

In some embodiments, referring to FIGS. 7, 14 and 15, the insulation base layer 4111 has a layer thickness ranging from 6 μm to 15 μm and/or the adhesion layer 4112 has a layer thickness ranging from 0.5 μm to 3 μm.

In some examples, the layer thickness of the insulation base layer 4111 ranges from 6 μm to 15 μm.

The insulation base layer 4111 has a layer thickness T ₁,6μm≤T₁≤15 μm, it being understood that the value of T ₁ may be 6 μm, 15 μm, and any value between 6 μm and 15 μm, and as an example, the value of T ₁ may be, but is not limited to, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm.

The design that T ₁ is more than or equal to 6 mu m can prevent burrs and realize insulation of the insulating base layer 4111, and the design that T ₁ is less than or equal to 15 mu m can prevent the thickness of the insulating base layer 4111 from being too large, thereby being beneficial to reducing the volume occupied by the first insulating piece 41 and improving the energy density of the battery cell 100.

By adopting the technical scheme of the embodiment, the internal insulation and the energy density of the battery cell 100 can be simultaneously considered.

In some examples, the layer thickness of the adhesive layer 4112 ranges from 0.5 μm to 3 μm.

The adhesive layer 4112 has a layer thickness T ₂,0.5μm≤T₂. Ltoreq.3 μm, it being understood that the value of T ₂ may be 0.3 μm, 3 μm, and any value between 0.3 μm and 3 μm, and for example, the value of T ₂ may be, but is not limited to, 0.3 μm, 0.5 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm.

The design that T ₂ is more than or equal to 0.5 mu m enables the bonding layer 4112 to have a certain thickness, so that the first insulating piece 41 can be stably bonded on the first pole piece 1, the insulating reliability of the first insulating piece 41 is good, and the design that T ₂ is less than or equal to 3 mu m enables the thickness of the bonding layer 4112 not to be too large, thereby being beneficial to reducing the volume occupied by the first insulating piece 41 and improving the energy density of the battery cell 100.

By adopting the technical scheme of the embodiment, the insulation reliability and the energy density of the battery cell 100 can be simultaneously considered.

In some examples, the insulation base layer 4111 has a layer thickness ranging from 6 μm to 15 μm and the adhesion layer 4112 has a layer thickness ranging from 0.5 μm to 3 μm.

By adopting the technical scheme of the embodiment, the insulation reliability and the energy density of the battery cell 100 can be simultaneously considered.

In one embodiment, referring to FIG. 7, the first insulator 41 has a dimension W in the first direction, where 3 mm≤W≤9 mm.

In some examples, the first insulating member 41 includes a first insulating portion 4121 and a second insulating portion 4122, w being equal to an overall dimension of the first insulating portion 4121 and the second insulating portion 4122 in the first direction.

It will be appreciated that the value of W may be 3mm, 9mm and any value between 3mm and 9mm, for example, the value of W may be, but is not limited to, 3mm, 4mm, 4.5mm, 5mm, 6mm, 6.5mm, 7mm, 8mm, 9mm.

The design that W is more than or equal to 3mm enables the first insulating piece 41 to have a certain size along the first direction, the first insulating piece 41 can better block burrs at the edge of the first connecting sub-portion 311, which is opposite to the active material layer 20, so that the internal insulation of the battery cell 100 is realized, and the design that W is less than or equal to 9mm enables the size of the first insulating piece 41 along the first direction not to be too large, thereby being beneficial to reducing the occupied volume of the first insulating piece 41 and improving the energy density of the battery cell 100.

By adopting the technical scheme of the embodiment, the insulation reliability and the energy density of the battery cell 100 can be simultaneously considered.

In some embodiments, 4.5 mm≤W≤6.5 mm.

By adopting the technical solution of this embodiment, the size of the first insulating member 41 is reasonable along the first direction, and the insulating reliability and the energy density of the battery cell 100 can be well considered.

In some embodiments, referring to fig. 7, the conductive portion 1211 has a thickness that is at least partially less than the thickness of the transition portion 1212.

In some examples, the minimum thickness of the conductive portion 1211 is t ₁ and the thickness of the transition portion 1212 is t ₂,t₁＜t₂.

In some examples, the transition 1212 is of an equal thickness structure or a substantially equal thickness structure, and the conductive portion 1211 is also of an equal thickness structure or a substantially equal thickness structure, the thickness of the transition 1212 being greater than the minimum thickness of the conductive portion 1211.

In some examples, the transition portion 1212 is of an equal thickness structure or a substantially equal thickness structure, the conductive portion 1211 may be of a non-equal thickness structure, and the thickness of the conductive portion 1211 is gradually increased along the direction in which the conductive portion 1211 points to the transition portion 1212, which may be specifically stepped or gradually increased, and the thickness of a portion of the conductive portion 1211 away from the transition portion 1212 is smaller than the thickness of the transition portion 1212.

By adopting the technical solution of this embodiment, the thickness of the transition portion 1212 may be greater than the thickness of at least a portion of the conductive portion 1211, the thickness of the transition portion 1212 is large, the overcurrent capability of the transition portion 1212 is improved, the heat generation of the transition portion 1212 is reduced, the melting risk of the first insulating member 41 is reduced, the reliability of the use of the battery cell 100 is improved, and in addition, the overcurrent capability of the transition portion 1212 is also improved, which is also beneficial to improving the quick-charge performance of the battery cell 100.

In some embodiments, referring to fig. 7, the conductive portion 1211 includes a first sub-portion 12111 and a second sub-portion 12112, the first sub-portion 12111 is connected between the second sub-portion 12112 and the transition portion 1212, the first sub-portion 12111 and the second sub-portion 12112 are covered with the active material layer 20, the thickness of the first sub-portion 12111 is greater than the thickness of the second sub-portion 12112, and the thickness of the transition portion 1212 is greater than or equal to the thickness of the first sub-portion 12111.

In some examples, the conductive portion 1211 may have a non-uniform thickness structure, and the conductive portion 1211 is divided into two parts along the direction in which the conductive portion 1211 points to the transition portion 1212, the part near the transition portion 1212 is a first sub-portion 12111, the part far from the transition portion 1212 is a second sub-portion 12112, and the first sub-portion 12111 and the second sub-portion 12112 are each covered with the active material layer 20.

In some examples, the first sub-portion 12111 may be an equal thickness structure, the second sub-portion 12112 may be an equal thickness structure, the first sub-portion 12111 may have a thickness greater than the second sub-portion 12112, the transition portion 1212 may have a thickness greater than or equal to the thickness of the first sub-portion 12111, the first sub-portion 12111 may have a thickness t ₃, and the second sub-portion 12112 may have a thickness t ₄,t₃＞t₄,t₂≥t₃,t₁＝t₄, wherein the first sub-portion 12111 and the second sub-portion 12112 form a stepped structure, the transition portion 1212 may have a thickness equal to the thickness of the first sub-portion 12111 such that the transition portion 1212 and the first sub-portion 12111 form an equal thickness structure, or the transition portion 1212 may have a thickness greater than the second sub-portion 12112 such that the first sub-portion 12111 and the transition portion 1212 form a stepped structure.

In some examples, the first sub-portion 12111 may also be a multi-segment structure, in which the thickness of each segment increases gradually along the direction of the conductive portion 1211 toward the transition portion 1212, and in examples, the first sub-portion 12111 includes a first segment and a second segment, the first segment is connected between the second segment and the second sub-portion 12112, in which the thickness of the first segment increases gradually along the direction of the conductive portion 1211 toward the transition portion 1212, the second segment is a substantially uniform thickness structure, the thickness of the second segment is equal to the thickness of the transition portion 1212, i.e., t ₃ may be equal to the thickness of the second segment, and the first segment increases gradually from the thickness of the second sub-portion 12112 to the thickness of the second segment. The thickness of the first section may be equal to the thickness of the transition 1212, and the thickness of the transition 1212 may also be greater than the thickness of the first section.

During the use of the battery cell 100, electrons generated by the active material layer 20 gradually collect onto the transition portion 1212 through the conductive portion 1211 along the direction of the conductive portion 1211 toward the transition portion 1212, and more electrons flow through the first sub-portion 12111 than through the second sub-portion 12112, which requires that the overcurrent capacity of the first sub-portion 12111 is greater than that of the second sub-portion 12112.

The thickness of the first sub-portion 12111 is greater than the thickness of the second sub-portion 12112 in the embodiment of the present application, so that the overcurrent capacity of the first sub-portion 12111 is greater than that of the second sub-portion 12112, which can reduce the limitation of current, improve the overcurrent capacity of the first pole piece 1, reduce the heat generation of the battery cell 100, and facilitate the improvement of the reliability of the use of the battery cell 100.

In some embodiments, referring to fig. 7, the current collector 10 further includes a conductive protection layer 13, the conductive protection layer 13 including a first protection portion 131 and a second protection portion 132, the first protection portion 131 being located between the first sub-portion 12111 and the active material layer 20, and the second protection portion 132 being located between the second sub-portion 12112 and the active material layer 20, wherein a thickness of the first protection portion 131 is smaller than a thickness of the second protection portion 132.

In some examples, a portion of the conductive protection layer 13 between the first sub-portion 12111 and the active material layer 20 may be the first protection portion 131, and a portion of the conductive protection layer 13 between the second sub-portion 12112 and the active material layer 20 may be the second protection portion 132 in the first direction, wherein the thickness of the first protection portion 131 is t ₅, and the thickness of the second protection portion 132 is t ₆,t₅＜t₆, and a difference in thickness of the current collector 10 at the first protection portion 131 and at the second protection portion 132 may be reduced.

In some examples, the first protection portion 131 may have an equal thickness structure or a different thickness structure, t ₅ may be the maximum thickness of the first protection portion 131, the second protection portion 132 may have an equal thickness structure or a different thickness structure, and t ₆ is the minimum thickness of the second protection portion 132.

Illustratively, the first protecting portion 131 includes a first portion and a second portion, the first portion is located between the first segment and the active material layer 20, the second protecting portion 132 is located between the second sub-portion 12112 and the active material layer 20, the thickness of the first portion gradually decreases along the direction of the conductive portion 1211 toward the transition portion 1212, and the second portion has a substantially uniform thickness structure, so that the thickness of the first protecting portion 131 can be adapted to the thickness of the first sub-portion 12111, and the surface of the conductive protecting layer 13 facing away from the insulating substrate 11 is close to a plane. Wherein t ₅ is equal to the thickness of the second portion.

By adopting the technical scheme of the embodiment, the surface of the conductive protection layer 13 facing away from the insulating substrate 11 is close to a plane, which is favorable for reducing rolling damage and improving the overcurrent capacity of the metal layer 12, and in addition, the winding bulge problem of the current collector 10 can be reduced.

In some embodiments, the conductive protection layer 13 further includes a third protection portion 133, where the third protection portion 133 covers a surface of the transition portion 1212 facing away from the insulating substrate 11, and a thickness of the third protection portion 133 is less than or equal to a thickness of the first protection portion 131.

In some examples, the conductive protection layer 13 may be divided into three parts along the first direction, a part close to the conductive member 30 is a third protection part 133, a part far away from the conductive member 30 is a second protection part 132, and a part located in the middle is a first protection part 131, wherein the thickness of the third protection part 133 is t ₇,t₇≤t₅＜t₆, and in addition, the thickness of the transition part 1212 is greater than or equal to the thickness of the first sub-part 12111, so that the thickness difference between the current collector 10 at the first protection part 131 and the third protection part 133 can be reduced, which is beneficial for the surface of the conductive protection layer 13 facing away from the metal layer 12 to approach the plane.

For example, the second protection portion 132, the third protection portion 133, the transition portion 1212 and the second sub-portion 12112 are all of equal thickness, the first sub-portion 12111 and the first protection portion 131 are all of unequal thickness, and the thickness of the first sub-portion 12111 and the thickness of the first protection portion 131 are adapted so that the surface of the conductive protection layer 13 facing away from the insulating substrate 11 is close to a plane.

By adopting the technical solution of this embodiment, the conductive protection layer 13 protrudes from the active material layer 20 by the arrangement of the third protection portion 133, so that the active material layer 20 and the metal layer 12 can be well separated, and in addition, the thickness of the third protection portion 133 is not too large, which is beneficial to reducing the waste of materials and saving the manufacturing cost of the battery cell 100.

In some embodiments, the metal layer 12 further includes at least one protrusion 122, the transition portion 1212 is connected between the protrusion 122 and the conductive portion 1211, the sum of the dimensions of all the protrusions 122 is smaller than the dimension of the transition portion 1212 along a second direction perpendicular to the thickness direction of the current collector 10, and the thickness of the protrusion 122 is greater than or equal to the thickness of the transition portion 1212.

For example, the thickness of the protrusion 122 may be equal to the thickness of the transition 1212, such that the protrusion 122 and the transition 1212 form an equal thickness structure.

For example, the thickness of the protrusion 122 may also be greater than the thickness of the transition 1212, such that the protrusion 122 and the transition 1212 form a stepped structure.

By adopting the technical scheme of the embodiment, the thickness of the protruding part 122 is larger, so that the overcurrent capacity of the protruding part 122 can be improved, the overcurrent capacity of the first pole piece 1 can be improved, the heating of the battery cell 100 can be reduced, and the quick charge performance and the use reliability of the battery cell 100 can be improved.

The battery cell 100 of the present application is described below with reference to some embodiments.

Example 1

In this embodiment, referring to fig. 3 to 12, the battery unit 100 includes an end cap 201, a housing 202 and an electrode assembly 101, the electrode assembly 101 is mounted in the housing 202, the end cap 201 covers the opening of the housing 202 to seal the housing 202, and the end cap 201 is provided with an electrode lead-out portion 2011.

In this embodiment, the electrode assembly 101 includes a first pole piece 1, a second pole piece 2 and a separator 3 that are wound, where the separator 3 is located between the first pole piece 1 and the second pole piece 2, and polarities of the first pole piece 1 and the second pole piece 2 are opposite, where the first pole piece 1 may be a positive pole piece, and the second pole piece 2 is a negative pole piece.

In the present embodiment, the first electrode sheet 1 includes the current collector 10, the active material layer 20, and the conductive member 30, the current collector 10 includes the insulating base 11, the metal layer 12, and the conductive protection layer 13, opposite surfaces of the insulating base 11 in the thickness direction are covered with the metal layer 12, surfaces of the metal layer 12 facing away from the insulating base 11 are covered with the conductive protection layer 13, and surfaces of the conductive protection layer 13 facing away from the insulating base 11 are covered with the active material layer 20.

In the present embodiment, the metal layer 12 includes a body portion 121 and at least one protrusion, the body portion 121 includes a transition portion 1212 and a conductive portion 1211, the protrusion 122, the transition portion 1212 and the conductive portion 1211 are arranged along a first direction, the transition portion 1212 is connected between the conductive portion 1211 and the protrusion 122, the active material layer 20 covers the conductive portion 1211, the protrusion 122 and the transition portion 1212 are not covered with the active material layer 20, and the first direction is perpendicular to the thickness direction of the current collector 10.

In the present embodiment, the conductive members 30 are welded to both the metal layers 12, the conductive members 30 include the first connection portions 31 and the second connection portions 32 that are connected, the first connection portions 31 are welded to the metal layers 12 to form the first solder marks 51, and the second connection portions 32 of the two conductive members 30 are welded to form the second solder marks 52.

In the present embodiment, the first solder mark 51 includes a first solder mark portion 511 and a second solder mark portion 512, the first connection portion 31 includes a first connection sub-portion 311 and at least one second connection sub-portion 312, the first connection sub-portion 311 is connected to the second connection portion 32 and the second connection sub-portion 312, the first connection sub-portion 311 is soldered with the transition portion 1212 to form the first solder mark portion 511, and the second connection sub-portion 312 is soldered with the protrusion portion 122 to form the second solder mark portion 512.

In the present embodiment, the number of the protruding portions 122 is plural, and the plurality of protruding portions 122 are arranged at intervals along the second direction, which is perpendicular to the thickness direction of the current collector 10.

In this embodiment, the electrode assembly 101 includes the first insulating member 41, the first insulating member 41 protrudes from the edge of the first connection sub-portion 311 away from the active material layer 20, and the first insulating member 41 covers the first and second solders 51 and 52.

In this embodiment, the first insulating member 41 includes a first insulating portion 4121 and a plurality of second insulating portions 4122, the first insulating portion 4121 is disposed continuously along the second direction, the first insulating portion 4121 covers the first connecting sub-portion 311, the plurality of second insulating portions 4122 are connected to the side portion of the first insulating portion 4121 away from the active material layer 20, the plurality of second insulating portions 4122 are sequentially connected along the second direction to form a whole, the second insulating portions 4122 cover the second connecting sub-portions 312 in a one-to-one correspondence, the adjacent two first insulating portions 4121 form a blocking portion 4131 with the portion of the first connecting sub-portion 311 corresponding to the region where the second connecting sub-portion 312 is not drawn out, and the blocking portions 4131 of the two second insulating portions 4122 are attached.

In this embodiment, the electrode assembly 101 further includes a second insulating member 42, the second insulating member 42 covers the surface of the transition portion 1212 facing away from the insulating base 11, the second insulating member 42 is located between the first connecting sub-portion 311 and the active material layer 20, and the first insulating member 41 covers the second insulating member 42.

Example two

This embodiment differs from the first embodiment in that, referring to fig. 13, the electrode assembly 101 does not include the second insulating member 42, one side of the first insulating member 41 is covered with the first solder mark 51, and the other side of the first insulating member 41 is covered with the active material layer 20.

Example III

This embodiment differs from the first embodiment in that, referring to fig. 13, 14 and 15, the first insulating member 41 includes an insulating base layer 4111 and an adhesive layer 4112, and the adhesive layer 4112 is adhered to the first pole piece 1.

In some embodiments, referring to the figures, a battery device 1100 is provided, including the battery cell 100 of the above embodiments.

The battery device 1100 according to the embodiment of the present application adopts the battery cell 100, and the battery cell 100 has good reliability in use, and the battery device 1100 has good reliability in use.

In some embodiments, an electrical device is provided, including a battery device 1100 as in the embodiments described above.

The power utilization device provided by the embodiment of the application adopts the battery device 1100, so that the use reliability of the battery device 1100 is good, and the improvement of the use reliability of the power utilization device is facilitated.

The foregoing description of various embodiments is intended to highlight differences between the various embodiments, which may be the same or similar to each other by reference, and is not repeated herein for the sake of brevity.

It should be noted that the above embodiments are only used to illustrate the technical solution of the present application, but not to limit the technical solution of the present application, and although the detailed description of the present application is given with reference to the above embodiments, it should be understood by those skilled in the art that the technical solution described in the above embodiments may be modified or some or all technical features may be equivalently replaced, and these modifications or substitutions do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the present application, and all the modifications or substitutions are included in the scope of the claims and the specification of the present application. In particular, the technical features mentioned in the respective embodiments may be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the claims.

Claims (53)

1. A battery cell, comprising:

A housing provided with an electrode lead-out portion;

An electrode assembly at least partially housed within the housing, the electrode assembly comprising a first electrode sheet and a first insulator, the first electrode sheet comprising a conductive member, a current collector, and an active material layer, the current collector comprising an insulating matrix and a metal layer;

The insulating substrate, the metal layer and the active material layer are stacked in the thickness direction of the current collector, and at least part of the metal layer is positioned between the insulating substrate and the active material layer;

The metal layer comprises a main body part, wherein the main body part comprises a transition part and a conductive part which are arranged along a first direction and connected, and the first direction is perpendicular to the thickness direction of the current collector;

The conductive member comprises a first connecting part and at least one second connecting part which are connected, the first connecting part is connected with the metal layer, the second connecting part is electrically connected with the electrode leading-out part, the first connecting part comprises a first connecting sub-part, the first connecting sub-part covers the surface of the transition part, which is opposite to the insulating substrate, along the direction that the conductive part points to the transition part, and the first insulating part protrudes out of the edge of the first connecting sub-part, which is far away from the active substance layer.

2. The battery cell of claim 1, wherein the first insulator projects from the first connector portion toward the edge of the active material layer along the direction in which the transition portion is directed toward the conductive portion.

3. The battery cell of claim 1, wherein an edge of the transition portion distal from the conductive portion is flush with an edge of the first connector portion distal from the active material layer in the first direction.

4. The battery cell of any one of claims 1-3, wherein the conductive portion has a dimension L ₁ and the transition portion has a dimension L ₂,0.8≤L₂/L₁≤1 in a second direction perpendicular to the first direction and the thickness direction of the current collector.

5. The battery cell of any one of claims 1-3, wherein the first connecting portion is welded to a surface of the metal layer, which is opposite to the insulating substrate, to form a first welding mark, and the first welding mark is located on one side, close to the transition portion, of the active material layer along the first direction.

6. The battery cell of claim 5, wherein the first insulator covers at least a portion of the first weld.

7. The battery cell of claim 5, wherein the first weld includes a first weld, and the first connector is welded to a surface of the transition portion facing away from the insulating substrate and forms the first weld.

8. The battery cell of claim 7, wherein the transition portion has a dimension L ₂ and the first weld portion has a dimension L ₃,0.8≤L₃/L₂≤1 in a second direction perpendicular to the first direction and the thickness direction of the current collector.

9. The battery cell of claim 7, wherein the first insulator covers at least a portion of the first weld.

10. The battery cell of claim 9, wherein the first insulator projects beyond the first solder portion toward the edge of the active material layer along the direction in which the transition portion is oriented, and/or wherein the first insulator projects beyond the edge of the first solder portion away from the active material layer along the direction in which the transition portion is oriented.

11. The battery cell of claim 7, wherein an edge of the first solder portion distal from the active material layer is flush with an edge of the first connector portion distal from the active material layer in the first direction.

12. The battery cell of claim 7, wherein the opposite edges of the transition portion are flush with the opposite edges of the first connection sub-portion, respectively, in a second direction perpendicular to the first direction and the thickness direction of the current collector.

13. The battery cell of claim 5, wherein the metal layer further comprises at least one protrusion, the transition portion being connected between the protrusion and the conductive portion;

The sum of the dimensions of all the projections is smaller than the dimension of the transition portion in a second direction perpendicular to the first direction and the thickness direction of the current collector;

The first connecting portion comprises at least one second connecting sub-portion, the second connecting sub-portion is connected between the first connecting sub-portion and the second connecting portion, the second connecting sub-portion covers the surface of the protruding portion, which faces away from the insulating substrate, and the second connecting sub-portions correspond to the protruding portions one by one.

14. The battery cell of claim 13, wherein the first weld includes at least one second weld, the second connector portion being welded to the corresponding tab and forming one of the second welds.

15. The battery cell of claim 14, wherein the first insulator covers at least a portion of the second weld.

16. The battery cell of claim 15, wherein the first insulator projects beyond the second solder to an edge of the active material layer in a direction in which the transition points toward the conductive portion, and/or wherein the first insulator projects beyond the second solder to an edge of the active material layer in a direction in which the conductive portion points toward the transition.

17. The battery cell of claim 13, wherein the first insulator projects beyond the edge of the second connector portion toward the active material layer along the direction of the transition portion toward the conductive portion, and/or wherein the first insulator projects beyond the edge of the second connector portion away from the active material layer along the direction of the conductive portion toward the transition portion.

18. The battery cell of claim 13, wherein the first insulating member comprises a first insulating portion and at least one second insulating portion, the first insulating portion covers the first connector portion, the second insulating portion covers the second connector portion, and the second insulating portion corresponds to the second connector portion one-to-one.

19. The battery cell of claim 18, wherein at least one of the opposite sides of the first insulating portion protrudes from the corresponding side of the first connector portion in the second direction.

20. The battery cell of claim 18, wherein the number of the protruding portions is plural, the number of the second connection sub-portions is plural, the protruding portions are arranged at intervals along the second direction, the second connection sub-portions are arranged at intervals along the second direction, the protruding portions and the second connection sub-portions are arranged in a one-to-one correspondence manner, the number of the second connection portions is plural, the second connection sub-portions are arranged at intervals along the second direction, the second connection sub-portions are connected with the second connection portions in a one-to-one correspondence manner, the second connection sub-portions are connected to edges of the first connection sub-portions facing away from the active material layer, the first connection sub-portions are arranged continuously along the second direction, the number of the second insulation portions is plural, the second insulation portions are arranged along the second direction, and the second insulation portions are arranged in a one-to-one correspondence manner.

21. The battery cell of claim 20, wherein two adjacent second insulating portions meet.

22. The battery cell of claim 5, wherein the first solder and the active material layer are spaced apart along the first direction.

23. The battery cell of claim 22, wherein the first solder is spaced from the active material layer in the first direction by a distance S ₁, wherein 0.3mm < S ₁ mm < 5mm, optionally 0.5mm < S ₁ mm < 2.8mm.

24. The battery cell of claim 22, wherein the electrode assembly includes a second insulator covering a surface of the metal layer facing away from the insulating substrate, the entire second insulator being located between the first weld and the active material layer.

25. The battery cell of claim 24, wherein the first connector portion is spaced apart from the active material layer in the first direction.

26. The battery cell of claim 25, wherein at least a portion of the second insulator is located between the first connector portion and the active material layer.

27. The battery cell of claim 26, wherein the electrode assembly further comprises a second pole piece having a polarity opposite the first pole piece, the second pole piece comprising a body functional portion and a tab portion arranged in the first direction, the end of the body functional portion adjacent to the transition portion having a first end face, the tab portion extending outwardly from the first end face, and wherein a projection of the first end face is located within a projection of the second insulating member in a thickness direction of the current collector.

28. The battery cell of claim 24, wherein one side of the first insulator covers the first connector portion and the other side of the first insulator covers at least a portion of the second insulator in the first direction.

29. The battery cell of any one of claims 1 to 3, wherein one side of the first insulating member covers the first connection sub-portion and the other side of the first insulating member covers at least a portion of the active material layer in the first direction.

30. The battery cell of claim 29, wherein the portion of the first insulating member that overlies the active material layer in the first direction has a dimension H, wherein 0.2 mm≤H≤1.0 mm, optionally 0.3 mm≤H≤0.8 mm.

31. The battery cell according to any one of claims 1 to 3, wherein the electrode assembly further comprises a second electrode sheet having a polarity opposite to that of the first electrode sheet, the second electrode sheet comprising a main body functional portion and a tab portion arranged in the first direction, an end portion of the main body functional portion near the transition portion having a first end face from which the tab portion extends outward, a side portion of the first connection sub-portion away from the active material layer in a direction toward the transition portion not protruding from the first end face, or a projection of the first end face in a thickness direction of the current collector being located within a projection of the first connection sub-portion.

32. The battery cell of any one of claims 1 to 3, wherein the electrode assembly further comprises a second pole piece with a polarity opposite to that of the first pole piece, the second pole piece comprises a main body functional part and a pole lug part, the main body functional part is arranged along the first direction, the end part, close to the transition part, is provided with a first end face, the pole lug part extends outwards from the first end face, and along the thickness direction of the current collector, the projection of the first end face is located in the projection of the first insulating part.

33. The battery cell according to any one of claims 1 to 3, wherein the number of the metal layers is two, the two metal layers are covered on opposite sides of the insulating substrate in the thickness direction of the current collector, the number of the active material layers is two, and the two active material layers are respectively covered on the conductive portions of the two metal layers;

The number of the conductive members is two, and the first connecting parts of the two conductive members are respectively connected with the two metal layers;

the number of the first insulating pieces is two, and the two first insulating pieces are respectively covered on the first connection sub-parts of the two conductive members.

34. The battery cell of claim 33, wherein a portion of the first insulating member protruding from the first connection sub-portion along the direction in which the conductive portion is directed toward the transition portion forms a blocking portion located at a side of the second connection portion along a second direction perpendicular to the first direction and the thickness direction of the current collector.

35. The battery cell of claim 34, wherein the barrier portions of the two first insulators are bonded.

36. The battery cell of claim 33, wherein the second connection portions of the two conductive members are welded and form a second weld.

37. The battery cell of claim 36, wherein the first insulator covers at least a portion of the second weld.

38. The battery cell of claim 37, wherein the first insulator protrudes from an edge of the second solder away from the active material layer in a direction in which the conductive portion is directed toward the transition portion.

39. The battery cell of any one of claims 1-3, wherein the current collector comprises a conductive protective layer, at least a portion of the conductive protective layer being located between the active material layer and the conductive portion.

40. The battery cell of claim 39, wherein the conductive protective layer protrudes from an end of the active material layer near the first connector portion in a direction in which the conductive portion is directed toward the transition portion.

41. The battery cell according to claim 40, wherein the protruding length of the conductive protective layer protruding from the active material layer along the direction in which the conductive portion is directed toward the transition portion is in the range of 0.3mm to 0.8mm.

42. The battery cell of claim 39, wherein the first connection portion is welded to a surface of the metal layer facing away from the insulating substrate to form a first weld, and the conductive protection layer and the first weld are spaced apart along the first direction.

43. The battery cell of any one of claims 1-3, wherein the first insulating member is connected to the first pole piece.

44. The battery cell of claim 43, wherein the first insulator comprises an insulation base layer and an adhesive layer bonded between the insulation base layer and the first pole piece.

45. The battery cell of claim 44, wherein the insulating base layer has a layer thickness ranging from 6 μm to 15 μm and/or the adhesive layer has a layer thickness ranging from 0.5 μm to 3 μm.

46. The battery cell of any one of claims 1-3, wherein the first insulator has a dimension W in the first direction, wherein 3 mm≤W≤9 mm, optionally 4.5 mm≤W≤6.5 mm.

47. The battery cell of any one of claims 1-3, wherein the conductive portion has a thickness at least partially less than a thickness of the transition portion.

48. The battery cell of claim 47, wherein the conductive portion comprises a first sub-portion and a second sub-portion, the first sub-portion being connected between the second sub-portion and the transition portion, the first sub-portion and the second sub-portion being covered with the active material layer, the first sub-portion having a thickness greater than a thickness of the second sub-portion, and the transition portion having a thickness greater than or equal to a thickness of the first sub-portion.

49. The battery cell of claim 48, wherein the current collector further comprises a conductive protective layer comprising a first protective portion and a second protective portion, the first protective portion being positioned between the first sub-portion and the active material layer, the second protective portion being positioned between the second sub-portion and the active material layer, wherein the thickness of the first protective portion is less than the thickness of the second protective portion.

50. The battery cell of claim 49, wherein the conductive protection layer further comprises a third protection portion, the third protection portion covers a surface of the transition portion facing away from the insulating substrate, and a thickness of the third protection portion is less than or equal to a thickness of the first protection portion.

51. The battery cell of any one of claims 1-3, wherein the metal layer further comprises at least one protrusion, the transition portion being connected between the protrusion and the conductive portion;

The sum of the dimensions of all the projections is smaller than the dimension of the transition portion in a second direction perpendicular to the first direction and the thickness direction of the current collector;

the thickness of the protruding portion is greater than or equal to the thickness of the transition portion.

52. A battery device comprising the battery cell according to any one of claims 1 to 51.

53. An electrical device comprising the battery device of claim 52.