CN119481502A

CN119481502A - Battery cell

Info

Publication number: CN119481502A
Application number: CN202411842472.1A
Authority: CN
Inventors: 刘杨; 王卿; 许久凌
Original assignee: China Innovation Aviation Technology Group Co ltd
Current assignee: China Innovation Aviation Technology Group Co ltd
Priority date: 2024-10-28
Filing date: 2024-10-28
Publication date: 2025-02-18
Also published as: CN119029433B; CN119029433A; CN119481501A

Abstract

The invention relates to the technical field of batteries, and discloses a battery. The battery comprises a battery shell, a first cover plate and an electric core, wherein openings are formed in two ends of the battery shell, the first cover plate seals one end opening of the shell, the first cover plate comprises a first cover plate body and a first bending part located at the edge of the first cover plate body, the first cover plate and the shell body form a containing cavity, the first bending part extends towards the containing cavity, the electric core is arranged in the containing cavity, an insulating part is arranged between the electric core and the first cover plate body, and the height of the insulating part is not lower than that of the first bending part. The first bending part extends towards the accommodating cavity, so that the maximization of the space utilization rate in the shell is guaranteed, and the capacity of the battery is further improved. The height of the insulating piece is higher than that of the first bending part or the height of the insulating piece is the same as that of the first bending part, and the insulating piece is filled in the groove formed by the first cover plate body and the first bending part, so that interference and influence of the first bending part on the battery cell are reduced.

Description

Battery cell

The application is a divisional application of the application patent application with the publication number of CN119029433A, the application date of the original application is 2024.10.28, the application number of the original application is 202411507438.9, and the application is a battery.

Technical Field

The invention relates to the technical field of batteries, in particular to a battery.

Background

Currently, the application field of batteries is wider and wider, and more electronic devices select rechargeable secondary batteries as power sources, such as mobile phones, notebook computers, electric tools, electric automobiles and the like. In the field of high-power battery application, such as new energy automobiles and energy storage, a plurality of single batteries are often required to be connected in series or in parallel for use, and meanwhile, high requirements are also put on battery cost.

The current battery cell generally includes battery case and the electric core of setting in battery case, and battery case includes casing and two apron, and during the production battery, in order to guarantee the welding strength of casing and apron, set up the hem on the apron, weld with the casing through the hem, if the apron body of two apron all is close to the setting of casing inside direction one side for the hem, leads to the inside space utilization of casing to descend to influence the capacity of battery.

Disclosure of Invention

In view of the above, the present invention provides a battery to solve the problem that the space utilization rate in the housing is low due to the arrangement of the cover body of the cover plate relative to the side of the flange close to the interior direction of the housing.

The invention provides a battery, which comprises a battery shell, wherein the battery shell comprises a shell body, a first cover plate and an electric core, openings are formed in two ends of the shell body, the first cover plate seals one end opening of the shell body and comprises a first cover plate body and a first bending part positioned at the edge of the first cover plate body, the first bending part is arranged around the first cover plate body and welded and fixed with the shell body, the first cover and the shell body form a containing cavity, the first bending part extends towards the containing cavity, the battery further comprises the electric core, the electric core is arranged in the containing cavity, the first cover plate is used for supporting the electric core, an insulating part is arranged between the electric core and the first cover plate body, and the height of the insulating part is not lower than that of the first bending part.

The battery cover has the beneficial effects that the first bending part extends towards the accommodating cavity, so that the maximization of the space utilization rate in the shell is ensured, the capacity of the battery is further improved, and the problem that the space utilization rate in the shell is low due to the fact that the cover body of the cover plate is arranged on one side, close to the inner direction of the shell, of the folded edge is effectively solved. The welding heat during the welding of the cover plate and the shell body can not be totally conducted to the battery cell, so that the situation that the diaphragm of the battery cell is damaged in the welding process is avoided, and the safety and the performance of the battery are guaranteed.

The height of the insulating piece is higher than that of the first bending part, or the height of the insulating piece is the same as that of the first bending part, so that the insulating piece can be filled in the groove formed by the first cover plate body and the first bending part, and interference and influence of the first bending part on the battery cell are reduced.

Drawings

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

Fig. 1 is a perspective view of a battery case according to an embodiment of the present invention;

FIG. 2 is a top view of the battery enclosure shown in FIG. 1;

FIG. 3 is a cross-sectional view of the battery housing of FIG. 2 taken in the A-A direction;

FIG. 4 is an enlarged partial schematic view of B in FIG. 3;

Fig. 5 is an enlarged partial schematic view of fig. 3C.

Reference numerals illustrate:

1. 101, welding area;

2. A first cover plate; 201, a first cover plate body, 202, a first bending part, 203, a groove;

3. the second cover plate comprises a second cover plate body 301 and a second bending part 302.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In the related art, the bending and extending directions of the folded edges of the two cover plates are opposite, and if the cover plate bodies of the two cover plates are arranged on one side, close to the inner direction of the shell, of the folded edges, the space utilization rate inside the shell is reduced, so that the capacity of the battery is affected.

In order to solve the above-described problems, an embodiment of the present invention is described below with reference to fig. 1 to 5.

According to an embodiment of the present invention, in one aspect, there is provided a battery including a battery case including a case body 1, a first cover plate 2, and a second cover plate 3.

Specifically, the housing body 1 is provided with openings at both ends.

The first cover plate 2 seals an opening at one end of the housing body 1, the first cover plate 2 comprises a first cover plate body 201 and a first bending part 202 located at the edge of the first cover plate body 201, and the first bending part 202 is arranged around the first cover plate body 201 and welded and fixed with the housing body 1.

The second cover plate 3 seals the opening at the other end of the housing body 1, the second cover plate 3 comprises a second cover plate body 301 and a second bending part 302 positioned at the edge of the second cover plate body 301, and the second bending part 302 is arranged around the second cover plate body 301 and is welded and fixed with the housing body 1.

The first cover plate 2, the second cover plate 3 and the housing body 1 form a receiving cavity, the first bending portion 202 extends toward the receiving cavity, and the second bending portion 302 extends toward a direction away from the receiving cavity.

According to the battery with the embodiment, the arrangement direction of the first cover plate 2 to the second cover plate 3 is taken as the first direction, the first bending part 202 of the first cover plate 2 and the second bending part 302 of the second cover plate 3 are bent and extend towards the first direction, namely, the bending directions and the extending directions of the first bending part 202 and the second bending part 302 are the same, the maximization of the space utilization rate in the shell is ensured, the capacity of the battery is further improved, and the problem that the space utilization rate in the shell is low due to the fact that the cover plate bodies of the two cover plates are arranged relative to one side of the folded edge close to the inner direction of the shell is effectively solved.

In the related art, the bending and extending directions of the folded edges of the two cover plates are opposite, so that the welding heat generated when the two cover plates are welded with the shell is fully conducted to the battery cell, and further the battery cell diaphragm is damaged, and the safety and the performance of the battery can be seriously affected.

In this embodiment, the bending directions of the two cover plates are the same, and the welding heat generated when the two cover plates are welded with the casing body 1 is not fully conducted to the battery cell, so that the situation that the diaphragm of the battery cell is damaged in the welding process is avoided, and the safety and performance of the battery are ensured.

It should be noted that, when the battery receives external impact, the design of two apron can provide better mechanical protection, strengthens the compressive capacity of battery when receiving external impact, reduces the electric core and because of the risk that external force is impaired, also can absorb and disperse external vibration to a certain extent, protects the inside subassembly of battery not damaged.

In one embodiment, as shown in fig. 3, the battery further includes a battery cell, the battery cell is disposed in the accommodating cavity, and the first cover plate 2 is used for supporting the battery cell. The battery cell is arranged on the first cover plate 2, and the influence of the weight of the battery cell on the welding seam of the first cover plate 2 and the shell body 1 is small. Therefore, the first cover plate 2 has a good bearing effect on the battery cells, and the safety, reliability and service life of the battery can be remarkably improved.

In the related art, the battery case includes casing and a apron, and the one end of casing sets up the opening, and the one end that the opening was kept away from to the casing has four bights, and the material of casing is the stainless steel, forms the casing through corrosion resistant plate punching press, because the ductility of stainless steel is relatively poor, and during the shaping casing, the bights are broken easily, and the shaping is difficult.

In order to solve the above-mentioned problem, in this embodiment, the two ends of the housing body 1 are provided with openings, the two ends of the housing body 1 are welded by the two cover plates, and the first bending portion 202 of the first cover plate extends toward the accommodating cavity, so that the welding reliability of the first cover plate 2 and the housing body 1 can be ensured. If the first bending portion 202 of the first cover plate 2 extends towards a direction away from the accommodating cavity, when the first cover plate 2 carries the battery cell, the battery cell applies a force on the first cover plate body 201 perpendicular to the first cover plate body 201, the force can be similar to a tearing force, and the first cover plate can be easily torn off from the housing body, so that the welding reliability of the first cover plate and the housing body is affected. After the first bending part 202 of the first cover plate 2 extends towards the accommodating cavity, the gravity of the battery cell acts on the first cover plate body 201 of the first cover plate 2, the gravity acts similarly to a tensile force, the influence on the welding seam of the first cover plate 2 and the shell body 1 is small, and the reliability of the welding seam of the shell is improved.

In one embodiment, as shown in fig. 5, the ratio of the height h1 to the thickness T1 of the first bending portion 202 ranges from 0.6 to 0.9. The height of the first bending part 202 refers to the dimension of the first bending part 202 in the direction perpendicular to the upper surface of the first cover plate body 201, that is, the height of the first bending part 202 refers to the distance from the top end of the first bending part 202 near the accommodating cavity to the side of the first cover plate body 201 near the accommodating cavity, and the thickness of the first bending part 202 refers to the distance from the outer wall surface of the first bending part 202 to the inner wall surface of the first bending part 202.

Specifically, the height h1 of the first bending portion 202, that is, the vertical dimension of the first bending portion 202 in fig. 5, and the thickness T1 of the first bending portion 202, that is, the lateral dimension of the first bending portion 202 in fig. 5.

Further, if the ratio of the height h1 of the first bending portion 202 to the thickness T1 is too small, this means that the height of the first bending portion 202 is too small or the thickness of the first bending portion 202 is too thick, if the first bending portion 202 is too thick, the interference of the first bending portion 202 to the battery cell is large, the battery cell is easily damaged, and if the height of the first bending portion 202 is too small, the welding area 101 between the first bending portion 202 and the case body is small, and the welding strength between the case body 1 and the first cover plate 2 is low.

If the ratio of the height h1 of the first bending portion 202 to the thickness T1 is too large, this indicates that the height of the first bending portion 202 is too large or the thickness of the first bending portion 202 is too small, if the height of the first bending portion 202 is too large, the electric core is affected, and the assembly of the battery is further affected, and if the thickness of the first bending portion 202 is too small, the welding slag is easily formed by welding the casing body 1 and the first bending portion 202, and the safety of the battery is affected.

Therefore, when the ratio of the height h1 to the thickness T1 of the first bending portion 202 is within the range of 0.6-0.9, the welding strength between the first cover plate 2 and the housing body 1 can be ensured, and meanwhile, the size of the first bending portion 202 is controlled, the interference of the first bending portion 202 to the battery cell is reduced, and the safety and the capacity of the battery cell are ensured.

Further, the height of the first bending portion 202 ranges from 0.3mm to 0.8mm, and the thickness ranges from 0.35mm to 0.9mm.

Specifically, the height of the first bending portion 202 may be preferably 0.4mm, 0.45mm, 0.48mm, 0.5mm, 0.55mm, 0.58mm, 0.6mm, 0.65mm, or 0.7mm. The thickness of the first bending portion 202 may be preferably 0.4mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.8mm or 0.85mm.

In one embodiment, as shown in fig. 5, the welding area 101 of the housing body 1 and the first bending portion 202 is located on the surface of the housing body 1, and the welding area 101 does not penetrate through the first bending portion 202. The welding area 101 does not penetrate through the first bending part 202, so that fine holes or cracks caused by complete penetration welding can be reduced, the tightness of the battery is improved, electrolyte leakage or external pollutants are prevented from entering the inside of the battery, the leakage risk is reduced, incomplete penetration welding retains the integrity of materials, the weakening of the materials possibly occurring during complete penetration welding is avoided, the structural strength of the shell and the cover plate is further maintained, the stress concentration can be reduced, and the fatigue resistance of the welding area 101 is improved.

The welding area 101 is a gray area in fig. 5.

In one embodiment, an insulating member (not shown in the figure) is disposed between the battery cell and the first cover plate body 201, that is, the insulating member is disposed between the battery cell and the first cover plate body 201, and the insulating member can effectively isolate the electrical connection member on the cover plate from the battery cell, so as to prevent the risk of short circuit caused by poor contact. The insulating piece can be used as a buffer layer, so that the mechanical stress between the cover plate and the battery cell is reduced, and the battery cell is prevented from being damaged due to vibration or collision. The insulating member generally has lower thermal conductivity, so that heat exchange between the battery cell and the external environment can be reduced, and the temperature stability of the battery cell can be maintained. The electrolyte around the cell may have a corrosive effect on the metal cover plate and the insulating member may prevent such chemical corrosion. The insulating member may enhance the sealing performance of the battery, preventing leakage of an electrolyte or entry of external contaminants into the inside of the battery.

Further, the height of the insulating member is not lower than the height of the first bending portion 202, i.e. the height of the insulating member is higher than the height of the first bending portion 202, or the height of the insulating member is the same as the height of the first bending portion 202, so that the insulating member is filled in the groove 203 formed by the first cover plate body 201 and the first bending portion 202, and interference and influence of the first bending portion 202 on the battery core are reduced. The height of the insulating piece refers to the distance from the top end of the insulating piece, which is close to the accommodating cavity, to the bottom end of the insulating piece, which is away from the accommodating cavity.

In particular, the higher insulation provides better electrical isolation against shorting between the cell and the cover plate due to contact. The higher insulating piece can be used as a buffer layer, so that direct contact between the cover plate and the battery cell is further reduced, and the battery cell is protected from mechanical stress. The higher insulating piece can better seal the inside of the battery, prevent pollutants such as moisture, dust from entering the inside of the battery, and improve the waterproof and dustproof grade of the battery. The higher insulation prevents electrolyte from leaking out of the gap between the cover plate and the housing. The higher insulating member can provide an additional thermal barrier, reduces heat exchange between the battery cell and the external environment, and helps to maintain the temperature stability of the battery cell.

In one embodiment, as shown in fig. 5, the ratio of the distance m between the welding area 101 of the housing body 1 and the first bending portion 202 and the side surface of the first bending portion 202 near the insulating member to the thickness T1 of the first bending portion 202 is 65% -90%. The distance m refers to the distance between the side of the welding area 101 near the insulating member and the side of the first bending portion 202 near the insulating member, that is, the lateral dimension between the inner side of the welding area 101 and the inner side of the first bending portion 202 in fig. 5.

Further, if the ratio of m to T1 is small, the welding heat will affect the battery core during welding, thereby affecting the safety of the battery, and if the ratio of m to T1 is large, the welding strength between the first cover plate 2 and the housing is small, and the welding firmness between the first cover plate 2 and the housing cannot be ensured.

Therefore, the ratio of m to T1 is in the range of 65% -90%, so that the welding strength of the first cover plate 2 and the shell can be ensured, the distance between the welding area 101 and the battery cell is ensured, and the influence of welding heat on the battery cell is reduced.

Specifically, the ratio of m to T1 may preferably be 70%, 75%, 78%, 70% or 85%.

In one embodiment, the distance between the first bending portion 202 and the insulating member is 0.1mm to 0.8mm. The distance between the first bending portion 202 and the insulating member refers to the distance between a side surface of the first bending portion 202 close to the insulating member and a side surface of the insulating member close to the first bending portion 202, that is, the distance between the inner side surface of the first bending portion 202 and the outer side surface of the insulating member.

Further, if the distance between the first bending portion 202 and the insulating member is larger, the possibility that the battery core contacts the first bending portion is increased, and the safety of the battery is affected, and if the distance between the first bending portion 202 and the insulating member is smaller, the welding heat generated when the first bending portion and the housing body 1 are welded affects the insulating member, and further the performance of the insulating member is affected.

Therefore, the distance between the first bending portion 202 and the insulating member is within the range of 0.1 mm-0.8 mm, so that the welding heat is ensured not to affect the insulating member during welding, and the possibility that the battery cell is contacted with the first bending portion is reduced.

Specifically, the distance of the first bending portion 202 from the insulating member may be preferably 0.2mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, or 0.7mm.

In one embodiment, as shown in fig. 3, the battery further includes a post provided on the second cap plate 3. Because the second bending part 302 of the second cover plate 3 extends along the direction deviating from the accommodating cavity, when the polar column is arranged on the second cover plate 3, the polar column is arranged in the recess formed by the second bending part 302 and the second cover plate body 301, so that the influence of the polar column on the whole height of the single battery can be reduced, and the height of the whole battery can be reduced. The pole is arranged on the second cover plate 3, so that the height of the protruding shell of the pole can be reduced, and the space utilization rate is improved. The pole post is connected with the pole lug of the battery core through a connecting sheet.

In one embodiment, the battery further comprises a battery cell, wherein the battery cell comprises a tab, and the tab is located on one side of the battery cell facing the second cover plate 3 and is connected with the pole. The arrangement position of the electrode lug can shorten the current transmission path and reduce the contact resistance, thereby improving the reliability of electrical connection. Because the distance between the electrode lug and the electrode post is relatively close, the current transmission efficiency is higher, the energy loss caused by long-distance transmission is reduced, the accumulation of mechanical stress can be reduced by a relatively short connection distance, and the abrasion or fracture caused by long-term use is avoided.

In one embodiment, as shown in fig. 4 and 5, the ratio of the height h1 of the first bending portion 202 to the height h2 of the second bending portion 302 is 0.6:1 to 0.88:1. Because the first bending part 202 is located inside the accommodating cavity, and the second bending part 302 is located outside the accommodating cavity, the length of the first bending part 202 needs to be smaller than that of the second bending part 302, so that the battery cell can be arranged higher in the height direction of the shell, the utilization rate of the internal space of the shell can be further improved, the capacity of the battery is improved, and meanwhile, the length of the second bending part 302 needs to be increased on the same side as that of the electrode column to prevent the heat generated during welding from influencing the electrode column.

Specifically, the ratio of the height h1 of the first bending portion 202 to the height h2 of the second bending portion 302 may be preferably 0.65:1, 0.7:1, 0.75:1, 0.8:1, or 0.85:1.

In one embodiment, as shown in fig. 4, the battery case is made of stainless steel, and the first cover plate 2, the second cover plate 3 and the case body 1 are made of stainless steel, and the stainless steel has the advantages of good corrosion resistance, high strength, excellent thermal expansion performance and heat preservation performance, good permeation resistance, good safety, good weldability and the like.

Further, the thickness T of the housing body 1 is 0.3mm to 0.8mm. The thickness of the housing body 1 refers to the distance between the inner surface and the outer surface of the housing body 1, i.e., the lateral dimension of the housing body 1 of fig. 4.

If the thickness of the shell is thicker, the overall weight of the battery is increased, and the weight of the electric automobile is further affected, and the thicker shell body 1 needs more materials, which increases the manufacturing cost, occupies more space, and is possibly not suitable for application scenes with limited space. If the thickness of the case is thinner, the case is not as thick in terms of mechanical strength and is easily deformed or damaged by external force, and the thinner case has weak ability in protecting the battery cell, the battery cell damage caused by external impact or extrusion may not be effectively prevented.

Therefore, the thickness T of the shell body 1 is 0.3 mm-0.8 mm, so that the strength of the shell body 1 can be ensured, and the material cost, the manufacturing cost and the occupied space can be controlled.

It is to be understood that in another embodiment, the battery case may be made of other materials, but is not limited thereto.

In one embodiment, the first cover plate 2 and the housing body 1 are fixed by penetration welding. The first cover plate 2 is welded and printed on the shell from the outer surface of the shell body 1 to the first bending part 202, and the penetration welding has the advantages of high strength connection, good sealing performance, wide applicability, high welding quality and the like.

It will be appreciated that in another embodiment, the first cover plate 2 and the housing body 1 may be welded by butt welding.

In one embodiment, the second cover plate 3 and the housing body 1 are also fixed by penetration welding. The outer surface of the shell body 1 is penetrated to the second bending part 302 for welding, and the penetration welding has the advantages of high strength connection, good sealing property, wide applicability, high welding quality and the like.

It will be appreciated that in another embodiment, the second cover plate 3 and the housing body 1 may be welded by butt welding.

In one embodiment, the first cover body 201 and the first bending portion 202 are formed by bending a sheet material, and the second cover body 301 and the second bending portion 302 are formed by bending a sheet material. The two cover plates are formed by processing plates, so that the processing is simple and convenient, and the manufacturing cost is reduced.

According to an embodiment of the invention, in another aspect, there is also provided a battery pack including the above battery.

Further, the battery pack combines a plurality of batteries and their associated components together to form a complete energy storage unit. The design and structural composition of the battery pack typically requires consideration of a number of factors including, but not limited to, safety, reliability, thermal management, electrical connections, and the like.

Although embodiments of the present invention have been described in connection with the accompanying drawings, various modifications and variations may be made by those skilled in the art without departing from the spirit and scope of the invention, and such modifications and variations fall within the scope of the invention as defined by the appended claims.

Claims

1. A battery is characterized by comprising a battery shell, wherein the battery shell comprises:

The shell body (1) is provided with openings at two ends;

the first cover plate (2) seals an opening at one end of the shell body (1), the first cover plate (2) comprises a first cover plate body (201) and a first bending part (202) positioned at the edge of the first cover plate body (201), and the first bending part (202) is arranged around the first cover plate body (201) and is welded and fixed with the shell body (1);

Wherein the first cover plate (2) and the shell body (1) form a containing cavity, and the first bending part (202) extends towards the containing cavity;

The battery also comprises a battery core, the battery core is arranged in the accommodating cavity, and the first cover plate (2) is used for supporting the battery core;

An insulating piece is arranged between the battery cell and the first cover plate body (201), and the height of the insulating piece is not lower than that of the first bending part (202).

2. The battery according to claim 1, wherein a ratio of the height h1 to the thickness T1 of the first bending portion (202) ranges from 0.6 to 0.9.

3. The battery according to claim 1, characterized in that a welding area of the case body (1) and the first bending portion (202) is located on a surface of the case body (1), and the welding area does not penetrate the first bending portion (202).

4. The battery according to claim 1, wherein a ratio of a distance m between a welding area of the case body (1) and the first bending portion (202) and a side surface of the insulating member near the first bending portion (202) to a thickness T1 of the first bending portion is in a range of 65% -90%.

5. The battery according to claim 1, wherein the first bending portion (202) is spaced from the insulating member by a distance of 0.1mm to 0.8mm.

6. The battery according to any one of claims 1 to 2, wherein the battery case is made of stainless steel, and the thickness T of the case body (1) is 0.3mm to 0.8mm.