CN118970312B

CN118970312B - Battery device and power device

Info

Publication number: CN118970312B
Application number: CN202411453113.7A
Authority: CN
Inventors: 王亮; 柯剑煌; 蔡加进; 李耀
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2024-10-17
Filing date: 2024-10-17
Publication date: 2025-02-14
Anticipated expiration: 2044-10-17
Also published as: CN118970312A

Abstract

The embodiment of the application provides a battery device and an electric device, wherein the battery device comprises a box body, a battery unit component and a plurality of connecting units, the battery unit component is positioned in the box body and comprises a plurality of confluence pieces and a plurality of battery units connected in series, each battery unit comprises at least two battery units connected in parallel through the two confluence pieces, each battery unit comprises an end cover, an electrode component, an adapter and an electrode terminal, the plurality of connecting units are arranged on at least one battery unit, the connecting units are arranged between the two adapters of the battery unit and the end covers of the battery unit in an insulating manner, or the connecting units are arranged between the two confluence pieces connected with the battery unit and the end covers of the battery unit in an insulating manner, and the connecting units are configured to enable the end covers and the adapter or the end covers and the confluence pieces to be connected in a conductive manner when the battery unit is in thermal runaway. The application can improve the reliability of the battery device.

Description

Battery device and electricity utilization device

Technical Field

The present application relates to the field of battery technology, and more particularly, to a battery device and an electric 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.

In the development of battery technology, how to improve the reliability of a battery device is one of the research directions in battery technology.

Disclosure of Invention

The application provides a battery device and an electric device, which can improve the reliability of the battery device.

The embodiment of the application provides a battery device, which comprises a box body, a battery unit assembly and a plurality of connecting units, wherein the battery unit assembly is positioned in the box body and comprises a plurality of converging pieces and a plurality of battery units connected in series, each battery unit comprises at least two battery units connected in parallel through the two converging pieces, each battery unit comprises an end cover, an electrode assembly, an adapter and an electrode terminal, the electrode assembly is electrically connected with the electrode terminal through the adapter, the electrode terminal is arranged on the end cover in an insulating manner, the adapter and the converging pieces are respectively arranged on the end cover in an insulating manner, the connecting units are respectively arranged on at least one battery unit in an insulating manner, or the connecting units are respectively arranged between the two adapters of the battery units and the end cover of the battery unit in an insulating manner, or the connecting units are respectively arranged between the two converging pieces connected with the battery units and the end cover of the battery unit in an insulating manner, and are configured to enable the end cover and the adapter or the end cover and the converging pieces to be electrically connected when the battery unit is in thermal runaway.

In the technical scheme, the battery device of the embodiment of the application is provided with the connecting unit, when the battery monomer is in thermal runaway, the connecting unit enables the end cover and the adapter or the end cover and the confluence part of the battery monomer in thermal runaway to be in conductive connection, so that the two battery monomers form a short circuit loop with larger current, the confluence part or the adapter in the short circuit loop is fused by the larger current, the short circuit loop is disconnected after the confluence part or the adapter is fused, the loop formed when the battery monomer in thermal runaway is regarded as a resistor is disconnected, and the parallel battery monomer almost does not generate heat any more, namely, the risk of thermal runaway is reduced, and the reliability of the battery device is improved.

In some embodiments, the connection unit includes a conductive member and an insulating member connected to each other, the conductive member is electrically connected to the end cap, and the insulating member is connected to the adapter member or the bus member, or the conductive member is electrically connected to the adapter member or the bus member, and the insulating member is connected to the end cap, and the insulating member has a melting point lower than that of the conductive member, and when the insulating member melts, the conductive member deforms and is electrically connected to a member to which the insulating member is connected before melting.

In the technical scheme, the connecting unit comprises the conductive piece and the insulating piece, the conductive piece is utilized to deform in thermal runaway to realize conductive connection of the end cover and the adapter piece or the end cover and the bus piece, and the connecting unit is reliable to use.

In some embodiments, the conductive member includes an elastic portion configured to be in a compressed state before the insulating member is melted and store elastic potential energy, and the elastic portion is configured to release the elastic potential energy to be elongated when the insulating member is melted, so that the conductive member achieves conductive connection of the end cover and the adapter member or the end cover and the bus member.

In the technical scheme, the elastic part releases elastic potential energy to stretch to realize conductive connection of the end cover and the adapter or the end cover and the bus piece, and the arrangement mode is reliable to use and low in cost.

In some embodiments, the resilient portion is a conductive structure and is used for conductive connection of the end cap and the adapter or the end cap and the buss.

In the above technical solution, the elastic portion is provided as a conductive structure, which is conductively connected with the component connected with the insulating member before melting after deformation, so that the structure of the connection unit can be simplified.

In some embodiments, the conductive member includes a deformable portion configured to deform thermally when the insulating member melts to conductively connect the end cap and the adapter member or the end cap and the bussing member.

In the technical scheme, the end cover and the adapter or the end cover and the bus piece are in conductive connection by utilizing the property that the deformable part is deformed under the temperature, and the mode is reliable to use.

In some embodiments, the insulating member comprises a protective cover, the conductive member comprises a conductive base, the protective cover is arranged on the conductive base and surrounds the conductive base to form a containing cavity, the deformable part of the conductive member is electrically connected to the conductive base and is located in the containing cavity, one of the conductive base and the insulating member is connected to the end cover, and the other one is connected to the adapter or the bus member.

In the technical scheme, the protective cover is arranged, and the deformable part of the conductive part is accommodated by surrounding the accommodating cavity by utilizing the protective cover and the conductive seat body, so that not only is the deformable part well protected, but also the possibility of short circuit caused by movement or deformation of the conductive part in the use process can be reduced by the protective cover, and the reliability of the battery device is improved.

In some embodiments, the protective cover is disposed on a side of the conductive housing facing the deformable portion of the conductive member.

In the technical scheme, the area of the conductive seat body can be increased, and the reliability of the electrical connection between the conductive seat body and the corresponding component is improved.

In some embodiments, the conductive member further comprises a conductive cover plate disposed in the receiving cavity and connected to an end of the deformable portion of the conductive member facing away from the conductive base, the conductive cover plate being configured to abut against a component to which the insulating member is connected prior to melting when the insulating member is melted.

In the technical scheme, the conductive cover plate is arranged, so that the contact area between the conductive piece and the part connected with the insulating piece before the insulating piece is melted is increased, and the overcurrent capacity of the connecting unit is improved.

In some embodiments, the side of the conductive cover facing away from the conductive base is provided with a plurality of conductive protrusions configured to abut against a component to which the insulating member is connected prior to melting when the insulating member is melted.

In the technical scheme, the conductive convex parts are arranged so that the conductive cover plate is still in good contact with the parts connected before the insulating part is melted after the conductive cover plate is inclined, and the use reliability of the connecting unit is improved.

In some embodiments, all of the battery cells of at least one battery cell are provided with a connection unit.

In the technical scheme, a short circuit loop can be formed and then cut off no matter which battery cell in the battery cells is in thermal runaway, so that the possibility of thermal runaway of the battery cells is further reduced, and the reliability of the battery device is improved.

In some embodiments, the insulator has a melting point T1, T1 satisfying 200 C.ltoreq.T1.ltoreq.400C.

In the technical scheme, the melting point of the insulating piece is set to be greater than or equal to 200 ℃ so as to meet the insulation requirement of the battery device in normal use. The melting point of the insulating member is limited to 400 ℃ or less so that the insulating member can be melted in time when thermal runaway occurs.

In some embodiments, T1 satisfies: T1 is less than or equal to 200 ℃ and less than or equal to 250 ℃.

In the technical scheme, the melting point of the insulating piece is further limited to be more than or equal to 200 ℃ so as to further meet the insulation requirement of the battery device in normal use. The melting point of the insulating member is further limited to 250 ℃ or less so that the insulating member can be melted more quickly when thermal runaway occurs.

In some embodiments, the battery cell is a square-case battery cell.

In the technical scheme, the adapter of the square shell battery monomer is easier to be heated and fused, and is more applicable.

In a second aspect, an embodiment of the present application further provides an electrical device, including the above battery device, where the battery device is used to provide electrical energy.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments of the present application will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present application, and other drawings may be obtained according to the drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic illustration 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 view showing an exploded structure of a battery cell and a bus bar according to some embodiments of the present application;

FIG. 4 is a top view of a battery cell and buss bar provided in some embodiments of the present application;

FIG. 5 is a cross-sectional view of the battery cell and buss member shown in FIG. 4 at A-A;

FIG. 6 is an enlarged view of FIG. 5 at B;

Fig. 7 is a schematic view illustrating another structure of a battery cell and a bus bar according to some embodiments of the present application;

FIG. 8 is another top view of a battery cell and buss bar provided in some embodiments of the present application;

FIG. 9 is a cross-sectional view of the battery cell and buss member shown in FIG. 8 at C-C;

fig. 10 is an enlarged view of fig. 9 at D;

fig. 11 is a schematic structural view of a connection unit in a battery device according to some embodiments of the present application;

FIG. 12 is a schematic view of the connection unit of FIG. 11 at another angle;

fig. 13 is a schematic view showing another structure of a connection unit in a battery device according to some embodiments of the present application;

fig. 14 is a schematic view showing a partial structure of a connection unit in a battery device according to some embodiments of the present application.

Reference numerals of the specific embodiments are as follows:

100. 200 parts of a vehicle, 200 parts of a battery device, 300 parts of a controller, 400 parts of a motor;

1. A case;

2. Cell unit component, 21, confluence piece, 22, cell unit, 23, cell unit, 231, end cover, 232, electrode component, 233, adapter piece, 234, electrode terminal, 235, lower plastic, 236, and shell;

3. Connection unit 31, conductive member 311, elastic part 312, deformable part 313, conductive base 314, conductive cover plate 315, conductive convex part 32, insulating member 321, protective cover 322, top wall 323, and side wall.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within 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 in the description of this application in this application 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 this application and the claims and the above description of the drawings are intended to cover non-exclusive inclusions. The terms first, second and the like in the description and in the claims or in the above-described figures, are used for distinguishing between different objects and not necessarily for describing a particular sequential or chronological order.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment 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.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "attached" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected, directly connected, indirectly connected through an intermediary, or may be in communication with the interior of two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

The term "and/or" in the present application is merely an association relation describing the association object, and indicates that three kinds of relations may exist, for example, a and/or B may indicate that a exists alone, while a and B exist together, and B exists alone. In the present application, the character "/" generally indicates that the front and rear related objects are an or relationship.

In the embodiments of the present application, the same reference numerals denote the same components, and detailed descriptions of the same components are omitted in different embodiments for the sake of brevity. It should be understood that the thickness, length, width, etc. dimensions of the various components in the embodiments of the application shown in the drawings, as well as the overall thickness, length, width, etc. dimensions of the integrated device, are merely illustrative and should not be construed as limiting the application in any way.

The term "plurality" as used herein refers to two or more (including two).

In the present application, the battery cells may include a lithium ion secondary battery cell, a lithium ion primary battery cell, a lithium sulfur battery cell, a sodium lithium ion battery cell, a sodium ion battery cell, or a magnesium ion battery cell, which is not limited in the embodiment of the present application. The battery cell may be in a cylindrical shape, a flat shape, a rectangular parallelepiped shape, or other shapes, which is not limited in this embodiment of the application.

The battery cell comprises an electrode assembly and electrolyte, wherein the electrode assembly comprises a positive electrode plate, a negative electrode plate and a separator. The battery cell mainly relies on metal ions to move between the positive pole piece and the negative pole piece to work. The positive electrode plate comprises a positive electrode current collector and a positive electrode active material layer, wherein the positive electrode active material layer is coated on the surface of the positive electrode current collector, the positive electrode current collector comprises a positive electrode coating area and a positive electrode lug connected to the positive electrode coating area, the positive electrode coating area is coated with the positive electrode active material layer, and the positive electrode lug is not coated with the positive electrode active material layer. Taking a lithium ion battery monomer as an example, the material of the positive electrode current collector can be aluminum, the positive electrode active material layer comprises a positive electrode active material, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium or lithium manganate and the like. The negative electrode plate comprises a negative electrode current collector and a negative electrode active material layer, wherein the negative electrode active material layer is coated on the surface of the negative electrode current collector, the negative electrode current collector comprises a negative electrode coating area and a negative electrode tab connected with the negative electrode coating area, the negative electrode coating area is coated with the negative electrode active material layer, and the negative electrode tab is not coated with the negative electrode active material layer. The material of the anode current collector may be copper, the anode active material layer includes an anode active material, and the anode active material may be carbon or silicon, or the like. The material of the separator may be PP (polypropylene) or PE (polyethylene), etc.

In a battery device, there are typically two or more battery cells connected in parallel to form a single battery cell and then connected in series in the entire circuit. In such a battery device, when one of the battery cells is thermally out-of-control, the battery cell in thermal out-of-control may be regarded as a resistor through which the battery cell connected in parallel forms a loop to discharge, and the battery cell connected in parallel continuously generates heat due to continuous discharge, which is liable to cause thermal out-of-control thereof, thereby causing thermal diffusion.

In view of this, the present application provides a battery device, in which a connection unit is provided, the connection unit is configured to be insulated during normal use, and an end cap and a junction element or an end cap and a bus bar are electrically connected when thermal runaway occurs in a battery cell, so as to form a short circuit loop of a relatively large current, and then fuse a mechanical element (e.g., the bus bar or the junction element) in the formed short circuit loop, and cut off the loop, so that the parallel battery cells do not continuously generate heat any more, the risk of thermal runaway is reduced, and the reliability of the battery device is improved.

The technical solutions described in the embodiments of the present application are applicable to various electric devices using battery devices, for example, mobile phones, portable devices, notebook computers, battery cars, electric toys, electric tools, vehicles, ships, spacecraft, etc., and for example, spacecraft includes airplanes, rockets, space shuttles, spacecraft, etc.

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

Fig. 1 is a schematic structural diagram of a vehicle 100 according to some embodiments of the present application, and fig. 2 is a schematic structural diagram of a battery device according to some embodiments of the present application.

As shown in fig. 1, the battery device 200 is provided inside the vehicle 100, and the battery device 200 may be provided at the bottom or the head or the tail of the vehicle 100. The battery device 200 may be used for power supply of the vehicle 100, for example, the battery device 200 may serve as an operating power source of the vehicle 100.

The vehicle 100 may also include a controller 300 and a motor 400, the controller 300 being configured to control the battery device 200 to power the motor 400, for example, for operating power requirements during start-up, navigation, and travel of the vehicle 100.

In some embodiments of the present application, the battery device 200 may not only serve as an operating power source for the vehicle 100, but also as a driving power source for the vehicle 100, providing driving power for the vehicle 100 instead of or in part instead of fuel oil or natural gas.

Referring to fig. 2, a battery device 200 (Battery Apparatus) according to an embodiment of the present application may include one or more battery cell assemblies 2 for providing voltage and capacity.

In some embodiments, the battery device 200 may be a battery Pack (battery Pack) including a case 1 and one or more battery cell assemblies 2, the battery cell assemblies 2 being accommodated in the case 1.

As an example, the battery cell assembly 2 may be a battery module, and the battery cell assembly 2 may be accommodated in the case 1 in such a manner that the battery module is fixed in the case 1.

As an example, the battery cell assembly 2 may be accommodated in the case 1 by directly fixing the plurality of battery cells 23 to the case 1.

As an example, the case 1 may include a first case and a second case. The first case and the second case are fastened such that a closed space is formed inside the case to receive the battery cell assembly 2. The closing means covering or closing, and can be sealing or unsealing. The first housing may be a top cover or a bottom plate.

As an example, the case 1 may include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected with the frame, so that a closed space is formed inside the box body 1 to accommodate the battery cell assembly 2.

As an example, the tank 1 may be part of the chassis structure of the vehicle 100. For example, the roof of the tank 1 may become at least a portion of the floor of the vehicle 100, or the frame of the tank 1 may become at least a portion of the cross members and stringers of the vehicle 100.

In some embodiments, the battery device 200 refers to an energy storage device comprising a case 1, at least one side of the case 1 being provided with a door. The energy storage device comprises an energy storage container, an energy storage electric cabinet and the like.

Fig. 3 is a schematic view showing an exploded structure of a battery cell and a bus bar according to some embodiments of the present application, fig. 4 is a top view of the battery cell and the bus bar according to some embodiments of the present application, fig. 5 is a cross-sectional view of the battery cell and the bus bar shown in fig. 4 at A-A, fig. 6 is an enlarged view of fig. 5 at B, fig. 7 is another schematic view of the battery cell and the bus bar according to some embodiments of the present application, fig. 8 is another top view of the battery cell and the bus bar according to some embodiments of the present application, fig. 9 is a cross-sectional view of the battery cell and the bus bar shown in fig. 8 at C-C, and fig. 10 is an enlarged view of fig. 9 at D.

As shown in fig. 2-10, the embodiment of the application provides a battery device 200, the battery device 200 includes a case 1, a battery unit assembly 2 and a connection unit 3, the battery unit assembly 2 is located in the case 1, the battery unit assembly 2 includes a plurality of bus bars 21 and a plurality of battery units 22 connected in series, the battery unit 22 includes at least two battery units 23 connected in parallel by the two bus bars 21, the battery unit 23 includes an end cover 231, an electrode assembly 232, a switching member 233 and an electrode terminal 234, the electrode assembly 232 and the electrode terminal 234 are electrically connected by the switching member 233, the electrode terminal 234 is arranged on the end cover 231 in an insulating manner, the switching member 233 and the bus bar 21 are respectively arranged on the end cover 231 in an insulating manner, the plurality of connection units 3 are arranged on the at least one battery unit 23, the connection units 3 are respectively arranged between the two switching members 233 of the battery unit 23 and the end cover 231 of the battery unit 23, or the connection units 3 are respectively arranged between the two bus bars 21 connected with the battery unit 23 and the end cover 231 of the battery unit 23. The connection unit 3 is configured to electrically connect the end cap 231 and the adapter 233 or the end cap 231 and the bus bar 21 when thermal runaway of the battery cell 23 occurs.

The battery unit 22 of the embodiment of the present application includes at least two or more battery cells 23, and the two or more battery cells 23 are connected in parallel by two bus bars 21. Illustratively, the busbar 21 is a busbar, which may be copper or aluminum.

The plurality of battery units 22 according to the embodiment of the present application are connected in series, as shown in fig. 2, and may be connected in series by bus bars 21, or may be connected in series by a structure such as a wire, both ends of which are respectively connected to two bus bars 21 in a conductive manner.

The electrode assembly 232 of the embodiment of the present application may be a wound electrode assembly, a laminated electrode assembly, or a hybrid structure of winding and lamination.

The connection unit 3 of the embodiment of the present application may be a semiconductor material, such as silicon, germanium, etc. The semiconductor material is an insulator at normal temperature, but after the temperature exceeds a certain temperature, electrons are activated, resulting in having conductive properties, and the connection unit 3 conducts the end cap 231 and the adapter 233 or the end cap 231 and the bus bar 21.

The battery cell 23 may be a square battery cell or a cylindrical battery cell, for example.

Optionally, the battery unit 23 further includes a housing 236, where the housing 236 is provided with an opening, and the end cap 231 covers the opening. The electrode assembly 232 and the adapter 233 are both disposed in the case 236.

The connection units 3 are arranged between the two adapters 233 of the battery unit 23 and the end cover 231 of the battery unit 23 in an insulating manner, and one or more connection units 3 can be arranged between the end cover 231 of the battery unit 23 and the adapters 233 of the battery unit 23.

In the embodiment of the application, the connection units 3 are arranged between the two bus members 21 connected with the battery cells 23 and the end covers 231 of the battery cells 23 in an insulating manner, and one or more connection units 3 can be arranged between the end covers 231 and the bus members 21.

Illustratively, taking the example that the battery unit 22 includes two battery cells 23 connected in parallel, and the connection unit 3 is disposed between the end cap 231 and the adapter 233 of the battery cell 23 where thermal runaway occurs, the connection unit 3 conducts the end cap 231 and the adapter 233 of the battery cell 23 where thermal runaway occurs, and the formed short circuit loop is that the positive electrode of the battery cell 23 is not runaway→the bus bar 21→the positive electrode terminal 234 of the battery cell 23 where the positive electrode of the battery cell 23 is runaway→the adapter 233 of the battery cell 23 where the positive electrode of the battery cell 23 is runaway→the end cap 231 of the battery cell 23 where the negative electrode of the battery cell 23 is runaway→the adapter 233 of the negative electrode of the battery cell 23→the negative electrode terminal 234 of the battery cell 23 where the other bus bar 21→the negative electrode of the battery cell 23 is not runaway. After the short circuit loop is formed, the larger current can fuse the adapter 233 or the bus bar 21 in the whole loop, so that after the short circuit loop is disconnected, the loop formed when the originally out-of-control battery cell 23 is regarded as a resistor is disconnected. The short circuit includes an internal circuit of the battery cell 23 that is not out of control, and the internal circuit of the battery cell 23 that is not out of control has the adapter 233.

Illustratively, taking the example that the battery unit 22 includes two battery cells 23 connected in parallel, and the connection unit 3 is disposed between the end cap 231 and the bus bar 21 of the battery cell 23 where thermal runaway occurs, the connection unit 3 conducts the end cap 231 and the bus bar 21, and a short circuit loop is formed, that is, a positive electrode of the battery cell 23 which is not runaway, the bus bar 21, the connection unit 3 at the positive electrode of the battery cell 23 which is runaway, the end cap 231 of the battery cell 23 which is runaway, the connection unit 3 at the negative electrode of the battery cell 23 which is runaway, the other bus bar 21, and the negative electrode of the battery cell 23 which is not runaway, after the short circuit loop is formed, a larger current can fuse the bus bar 21 or the adapter 233 in the whole loop, so that after the short circuit loop is disconnected, the loop formed when the battery cell 23 which is originally runaway is regarded as a resistor is also disconnected. The short circuit includes an internal circuit of the battery cell 23 that is not out of control, and the internal circuit of the battery cell 23 that is not out of control has the adapter 233.

Even if the connection unit 3 in the battery cell 23 connected in parallel with the out-of-control battery cell 23 conducts the end cap 231 and the adapter 233 or the end cap 231 and the bus bar 21 of the battery cell 23 connected in parallel, the battery cell 23 is short-circuited by the end cap 231 itself to form a larger current fusing adapter 233 or the bus bar 21, and the loop that can be formed by the battery cell 23 connected in parallel and the out-of-control battery cell 23 is also broken.

Illustratively, the connection unit 3 is disposed between the end cap 231 of the battery cell 23 and the two adapters 233 of the battery cell 23 in an insulating manner, and the battery cell 23 further includes a lower plastic 235, wherein the lower plastic 235 is disposed between the end cap 231 and the electrode assembly 232 and is provided with a through hole through which the connection unit 3 passes.

The thermal runaway initiation condition of the embodiment of the application can be temperature or pressure, namely, the pressure is too high to initiate thermal runaway.

In the battery device 200 of the embodiment of the application, when the battery cell 23 is in thermal runaway, the connection unit 3 enables the end cover 231 and the adapter 233 of the battery cell 23 or the end cover 231 and the bus bar 21 to be electrically connected, so that the two battery cells 23 form a short circuit loop with larger current, the bus bar 21 or the adapter 233 in the short circuit loop is fused by the larger current, the short circuit loop formed by the battery cell 23 in thermal runaway and the battery cell 23 in parallel is disconnected after the bus bar 21 or the adapter 233 is fused, the loop formed when the battery cell 23 in thermal runaway is regarded as a resistor is disconnected, and the battery cell 23 in parallel almost does not generate heat any more, namely the risk of thermal runaway is reduced, and the reliability of the battery device 200 is improved.

In some embodiments, the connection unit 3 includes a conductive member 31 and an insulating member 32 connected, the conductive member 31 is electrically connected to the end cap 231 and the insulating member 32 is connected to the adapter member 233 or the bus member 21, or the conductive member 31 is electrically connected to the adapter member 233 or the bus member 21 and the insulating member 32 is connected to the end cap 231, and the melting point of the insulating member 32 is lower than that of the conductive member 31, and when the insulating member 32 is melted, the conductive member 31 is deformed and is electrically connected to a part to which the insulating member 32 is connected before being melted.

The material of the conductive member 31 in the embodiment of the present application may be aluminum, copper, nickel, etc., and the material of the insulating member 32 may be rubber, polypropylene (PP), polyethylene (PE), ‌ Polyimide (PI).

The conductive member 31 and the insulating member 32 according to the embodiment of the present application may be arranged along the arrangement direction of the two members to which the conductive member 31 is connected, the conductive member 31 is used for deformation, and the insulating member 32 provides an insulating effect under normal working conditions. The conductive member 31 and the insulating member 32 according to the embodiment of the present application may be abutted against each other, or may be fixedly connected, for example, by bonding or welding.

The conductive member 31 according to the embodiment of the present application may be electrically connected against the connected component, or may be fixedly connected to the connected component, for example, by a bolt lock, welding, or clamping.

The insulating member 32 according to the embodiment of the present application may be abutted against the connected components, or may be fixedly connected to the connected components, for example, by bonding or welding.

The conductive member 31 of the embodiment of the present application is electrically connected to the end cap 231, and the insulating member 32 is connected to the adapter member 233 or the bus member 21, or the conductive member 31 is electrically connected to the adapter member 233 or the bus member 21, and the insulating member 32 is connected to the end cap 231, which includes the following schemes:

the conductive member 31 is electrically connected to the end cap 231, and the insulating member 32 is connected to the adapter member 233, as shown in fig. 6;

The conductive member 31 is electrically connected to the end cap 231, and the insulating member 32 is connected to the bus bar 21, as shown in fig. 10;

the conductive member 31 is electrically connected to the adapter member 233, and the insulating member 32 is connected to the end cap 231;

the conductive member 31 is electrically connected to the bus bar 21, and the insulating member 32 is connected to the end cap 231.

The connection unit 3 is provided to include the conductive member 31 and the insulating member 32, and the conductive connection of the end cap 231 and the adapter 233 or the end cap 231 and the bus bar 21 is achieved by using the deformation of the conductive member 31 at the time of thermal runaway, and the connection unit 3 is not only reliable in use but also low in cost.

Fig. 11 is a schematic structural view of a connection unit in a battery device according to some embodiments of the present application, and fig. 12 is a schematic structural view of the connection unit shown in fig. 11 at another angle.

Referring to fig. 11 and 12, in some embodiments, the conductive member 31 includes an elastic portion 311, the elastic portion 311 is configured to be in a compressed state before the insulating member 32 is melted and store elastic potential energy, and the elastic portion 311 is configured to release the elastic potential energy to be elongated after the insulating member 32 is melted, so that the conductive member 31 achieves conductive connection of the end cap 231 and the adapter 233 or the end cap 231 and the bus bar 21.

The elastic part 311 of the embodiment of the present application may be a spring, a metal elastic sheet folded in a Z-shape along the length direction, or other extensible structures.

Illustratively, the elastic portion 311 is elongated by releasing elastic potential energy against the member to which the insulator 32 is connected before melting, thereby achieving conductive connection of the end cap 231 and the adapter 233 or the end cap 231 and the bus bar 21.

For example, the elastic portion 311 may be an insulating elastic body such as rubber, and the upper end of the elastic portion is connected to a conductive cover plate structure, the lower end of the elastic portion is connected to a conductive bottom plate structure, the cover plate structure and the bottom plate structure are electrically connected through a wire, the length of the wire has a margin, and the insulating member 32 is connected to the cover plate structure. When the insulating member 32 melts, the elastic portion 311 releases elastic potential energy to extend, and drives the cover structure to abut against the component connected to the insulating member 32 before melting to realize conductive connection.

The elastic portion 311 releases elastic potential energy to stretch to realize conductive connection between the end cover 231 and the adapter 233 or between the end cover 231 and the bus bar 21, so that the arrangement is reliable in use and low in cost.

In some embodiments, the elastic portion 311 is a conductive structure and is used for conductive connection of the end cap 231 and the adapter 233 or the end cap 231 and the bus bar 21.

Illustratively, the resilient portion 311 is a metallic conductive structure, such as a spring.

The elastic portion 311 of the embodiment of the present application may or may not directly abut against the component before the melting of the insulating member 32 when the insulating member 32 is melted.

The elastic portion 311 is provided as a conductive structure, which is conductively connected to the member to which the insulator 32 is connected before melting after deformation, and the structure of the connection unit 3 can be simplified.

Fig. 13 is a schematic view illustrating another structure of a connection unit in a battery device according to some embodiments of the present application.

Referring to fig. 13, in some embodiments, the conductive member 31 includes a deformable portion 312, the deformable portion 312 being configured to deform thermally when the insulating member 32 melts to conductively connect the end cap 231 and the adapter 233 or the end cap 231 and the bus bar 21.

The deformable portion 312 of the present embodiment may be a memory alloy that expands or otherwise deforms after being heated, for example, from a bent state to a straightened state, so that the end cap 231 and the adapter 233 or the end cap 231 and the bus bar 21 are electrically connected.

The end cap 231 and the adapter 233 or the end cap 231 and the bus bar 21 are electrically connected by the deformation property of the deformable portion 312 caused by temperature, which is reliable in use.

In some embodiments, the insulating member 32 includes a protective cover 321, the conductive member 31 includes a conductive base 313, the protective cover 321 is covered on the conductive base 313 and forms a receiving cavity with the conductive base 313, a deformable portion of the conductive member 31 is electrically connected to the conductive base 313 and is located in the receiving cavity, one of the conductive base 313 and the insulating member 32 is connected to the end cap 231, and the other is connected to the adapter 233 or the bus bar 21.

The protective cover 321 includes a side wall 323 and a top wall 322, wherein the side wall 323 is connected to an outer periphery of the top wall 322, the side wall 323 may be a curved wall, the curved wall is arranged around a circle, the side wall 323 may also be a straight wall, and a plurality of straight walls are sequentially connected at an angle.

The deformable portion of the conductive member 31 according to the embodiment of the present application may be the elastic portion 311 or the deformable portion 312.

The protective cover 321 according to the embodiment of the present application may or may not abut against the member to which the conductive member 31 is connected.

The protective cover 321 and the connected components may be connected by a fixed connection, such as an adhesive or a weld, for example.

Illustratively, the conductive mount 313 is a plate-like member, and the conductive mount 313 is fixedly and conductively coupled to the coupled member, such as by welding or bonding with conductive glue.

The protective cover 321 is provided, and the deformable portion of the conductive member 31 is accommodated by enclosing the protective cover 321 and the conductive base 313 to form an accommodating cavity, so that not only is the deformable portion well protected, but also the protective cover 321 can reduce the possibility of short circuit caused by movement or deformation of the conductive member 31 in the use process, and the reliability of the battery device 200 is improved.

In some embodiments, the protective cover 321 covers a side of the conductive base 313 facing the deformable portion of the conductive member 31.

The protective cover 321 is, for example, fixedly connected to the conductive mount 313, for example by welding or adhesive bonding.

By this arrangement, the area of the conductive base 313 can be increased, and the reliability of the electrical connection between the conductive base 313 and the corresponding component can be improved.

In some embodiments, the conductive element 31 further includes a conductive cover 314, where the conductive cover 314 is disposed in the receiving cavity and is connected to an end of the deformable portion of the conductive element 31 facing away from the conductive base 313, and where the conductive cover 314 is configured to abut a component to which the insulating element 32 is connected prior to melting when the insulating element 32 is melted.

Illustratively, the conductive cover 314 is configured to conform to the components to which the insulator 32 was attached prior to melting when the insulator 32 was melted.

Illustratively, the conductive cover plate 314 is integrally formed with or welded to the deformable portion of the conductive member 31.

The conductive cover 314 is provided to increase the contact area of the conductive member 31 with the member connected before the melting of the insulating member 32 when the insulating member 32 is melted, thereby improving the overcurrent capability of the connection unit 3.

Referring to fig. 14, in some embodiments, a plurality of conductive protrusions 315 are disposed on a side of the conductive cover 314 facing away from the conductive base 313, and the plurality of conductive protrusions 315 are configured to abut against a component to which the insulating member 32 is connected before the insulating member 32 is melted.

The shape of the plurality of conductive bumps 315 of embodiments of the present application may be the same or different.

The conductive protruding 315 is provided so as to be in good contact with the parts to which the insulating member 32 is connected before melting after the conductive cap 314 is tilted, improving the reliability of the use of the connection unit 3.

In some embodiments, all of the battery cells 23 of at least one battery cell 22 are provided with a connection unit.

Alternatively, one battery unit 22 has two battery cells 23, and both battery cells 23 are provided with the connection unit 3.

With this arrangement, a short circuit can be formed and then cut off in any of the battery cells 23 in the battery cells 22, further improving the reliability of the battery device 200.

In some embodiments, the corresponding connected components of the insulating member 32 are fixedly connected with the insulating member 32, and/or the corresponding connected components of the conductive member 31 are fixedly connected with the conductive member 31.

The components of the insulation member 32 according to the embodiment of the present application that are correspondingly connected with the insulation member 32 may be connected by welding or bonding.

The components corresponding to the conductive members 31 in the embodiment of the present application may be connected to the conductive members 31 by clamping, welding, or fastening by fasteners.

With this arrangement, the tightness of connection of the connection unit 3 with other components in the battery device 200 can be improved, thereby reducing the possibility of displacement of the connection unit 3 during use.

In some embodiments, the insulator 32 has a melting point T1, T1 satisfying 200 C.ltoreq.T1.ltoreq.400C.

Alternatively, the value of T1 may be 200 ℃, 250 ℃, 300 ℃, 350 ℃, or 400 ℃.

The melting point of the insulating member 32 is set to 200C or more to satisfy the insulation requirement of the battery device 200 in normal use. The melting point of the insulating member 32 is limited to 400 ℃ or less so that the insulating member 32 can be melted in time when thermal runaway occurs.

Alternatively, the value of T1 may be 200 ℃, 210 ℃, 220 ℃, 230 ℃, 240 ℃, or 250 ℃.

The melting point of the insulating member 32 is further limited to 200C or more to further satisfy the insulation requirement of the battery device 200 in normal use. The melting point of the insulating member 32 is further limited to 250 ℃ or less so that the insulating member 32 can be melted more quickly when thermal runaway occurs.

In some embodiments, the battery cell 23 is a square-case battery cell 23.

The adapter 233 of the square battery cell 23 is easier to be fused by heating and is more suitable.

The embodiment of the application also provides an electricity utilization device, which comprises the battery device 200, wherein the battery device 200 is used for providing electric energy.

Referring to fig. 2-12, an embodiment of the application provides a battery device 200, the battery device 200 includes a case 1, a battery unit assembly 2 and a connection unit 3, the battery unit assembly 2 is located in the case 1, the battery unit assembly 2 includes a plurality of bus bars 21 and a plurality of battery units 22 connected in series, the battery unit 22 includes at least two battery units 23 connected in parallel by the two bus bars 21, the battery unit 23 includes an end cover 231, an electrode assembly 232, a switching member 233 and an electrode terminal 234, the electrode assembly 232 and the electrode terminal 234 are electrically connected by the switching member 233, the electrode terminal 234 is arranged on the end cover 231 in an insulation manner, the switching member 233 and the bus bar 21 are respectively arranged on the end cover 231 in an insulation manner, the plurality of connection units 3 are arranged on the at least one battery unit 23, the two switching members 233 of the battery unit 23 are respectively arranged on the end cover 231 of the battery unit 23 in an insulation manner, or the two bus bars 21 connected with the battery unit 23 are respectively arranged on the connection unit 3 in an insulation manner between the two bus bars 21 and the end cover 231 of the battery unit 23. The connection unit 3 is configured to electrically connect the end cap 231 and the adapter 233 or the end cap 231 and the bus bar 21 when thermal runaway of the battery cell 23 occurs. The connection unit 3 includes a conductive member 31 and an insulating member 32 connected to each other, the conductive member 31 is electrically connected to the end cap 231, and the insulating member 32 is connected to the adapter member 233 or the bus bar 21. The conductive member 31 includes an elastic portion 311, the elastic portion 311 is configured to be in a compressed state and store elastic potential energy before the melting of the insulating member 32, and the elastic portion 311 is configured to be extended by releasing the elastic potential energy after the melting of the insulating member 32, so as to achieve conductive connection of the end cap 231 and the adapter 233 or the end cap 231 and the bus bar 21. The insulating member 32 includes a protecting cover 321, the conductive member 31 includes a conductive base 313, the protecting cover 321 is covered on the conductive base 313 and encloses with the conductive base 313 to form a receiving cavity, the deformable portion of the conductive member 31 is electrically connected to the conductive base 313 and located in the receiving cavity, the conductive base 313 is connected to the end cover 231, and the protecting cover 321 is connected to the adapter 233 or the bus member 21. The conductive member 31 further includes a conductive cover 314, where the conductive cover 314 is disposed in the accommodating cavity and is connected to an end of the deformable portion of the conductive member 31 facing away from the conductive base 313, and where the conductive cover 314 is configured to abut against a component to which the insulating member 32 is connected before the insulating member 32 is melted. All the battery cells 23 of at least one battery cell 22 are provided with a connection unit. The battery cell 23 is a square case battery cell 23.

It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other.

It should be noted that the above-mentioned embodiments are merely for illustrating the technical solution of the present application, and not for limiting the same, and although the present application has been described in detail with reference to the above-mentioned embodiments, it should be understood by those skilled in the art that the technical solution described in the above-mentioned embodiments may be modified or some technical features may be equivalently replaced, and these modifications or substitutions do not make the essence of the corresponding technical solution deviate from the spirit and scope of the technical solution of the embodiments of the present application.

Claims

1. A battery device, comprising:

Box;

A battery cell assembly is located in the box, the battery cell assembly includes a plurality of busbars and a plurality of battery cells connected in series, the battery cell includes at least two battery cells connected in parallel through two busbars, the battery cell includes an end cap, an electrode assembly, a transition piece and an electrode terminal, the electrode assembly is electrically connected to the electrode terminal through the transition piece, the electrode terminal is insulated and arranged on the end cap, and the transition piece and the busbar are respectively insulated and arranged on the end cap;

A plurality of connection units are arranged on at least one of the battery cells, wherein the connection units are insulated between the two adapters of the battery cell and the end covers of the battery cell, or the connection units are insulated between the two busbars connected to the battery cell and the end covers of the battery cell, and the connection units are configured to conductively connect the end covers and the adapters or the end covers and the busbars when thermal runaway occurs in the battery cell, so as to cause the adapters or the busbars to fuse.

2. The battery device according to claim 1, characterized in that the connecting unit comprises a conductive member and an insulating member connected to each other;

The conductive member is electrically connected to the end cover, and the insulating member is connected to the adapter or the current collector, or the conductive member is electrically connected to the adapter or the current collector, and the insulating member is connected to the end cover;

The melting point of the insulating member is lower than that of the conductive member. When the insulating member melts, the conductive member is deformed and conductively connected to the component to which the insulating member was connected before melting.

3. The battery device according to claim 2 is characterized in that the conductive member includes an elastic portion, which is configured to be in a compressed state and store elastic potential energy before the insulating member melts, and the elastic portion is configured to release the elastic potential energy and stretch when the insulating member melts, so that the conductive member can achieve a conductive connection between the end cover and the adapter or between the end cover and the busbar.

4 . The battery device according to claim 3 , wherein the elastic portion is a conductive structure and is used for conductive connection between the end cover and the adapter or between the end cover and the current collector.

5. The battery device according to claim 2, characterized in that the conductive member comprises a deformable portion, and the deformable portion is configured to be deformed by heat when the insulating member melts, so as to conductively connect the end cover and the transition member or the end cover and the busbar.

6. The battery device according to claim 2 is characterized in that the insulating member includes a protective cover, the conductive member includes a conductive seat, the protective cover is disposed on the conductive seat and is surrounded by the conductive seat to form a receiving cavity, the deformable portion of the conductive member is electrically connected to the conductive seat and is located in the receiving cavity, one of the conductive seat and the insulating member is connected to the end cover, and the other is connected to the adapter or the busbar.

7 . The battery device according to claim 6 , wherein the protective cover is disposed on a side of the conductive base body facing the deformable portion of the conductive member.

8. The battery device according to claim 6 is characterized in that the conductive member also includes a conductive cover plate, which is arranged in the accommodating cavity and connected to an end of the deformable portion of the conductive member away from the conductive seat, and the conductive cover plate is configured to abut against the component connected to the insulating member before the insulating member melts when the insulating member melts.

9 . The battery device according to claim 8 , wherein a plurality of conductive protrusions are provided on a side of the conductive cover plate facing away from the conductive seat, and the plurality of conductive protrusions are configured to abut against components connected to the insulating member before the insulating member melts when the insulating member melts.

10 . The battery device according to claim 1 , wherein all battery cells of at least one of the battery units are provided with the connecting unit.

11. The battery device according to any one of claims 2 to 9, characterized in that the melting point of the insulating member is T1, and T1 satisfies: 200°C ≤ T1 ≤ 400°C.

12 . The battery device according to claim 11 , wherein T1 satisfies: 200° C. ≤ T1 ≤ 250° C.

13. The battery device according to any one of claims 1 to 9, characterized in that the battery cell is a square shell battery cell.

14. An electrical device, characterized in that it comprises a battery device as described in any one of claims 1 to 13, wherein the battery device is used to provide electrical energy.