Battery cell structure and battery

Abstract

The utility model relates to the technical field of batteries, and discloses a battery cell structure and a battery, the battery cell structure comprises: a housing, the inner wall of which is enclosed to form an accommodating cavity; the pole group is arranged in the accommodating cavity; the cover plate assembly is arranged on one side, in the first direction, of the shell, and the cover plate assembly is suitable for fixing the pole group in the containing cavity; the base plate is arranged between the pole group and the cover plate assembly, one side of the base plate in the thickness direction is attached to the pole group, and the other side of the base plate abuts against the cover plate assembly. According to the battery cell structure provided by the utility model, the base plate is arranged between the pole group and the cover plate components, and when the cover plate components on the two sides of the battery cell push the pole group into a shell, one side of the base plate along the thickness direction of the base plate is attached to the pole group, and the other side of the base plate is propped against the cover plate components, so that the pole group is stressed more uniformly; and the risks of damage and tearing of the pole piece are reduced, the pole group can be fully fixed, the movement space of the pole group is reduced, and movement of the pole group is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a battery core structure and a battery. Background Art

[0002] As lithium-ion battery technology matures, lithium-ion batteries are widely used as power batteries in electric vehicles and energy storage fields, and the requirements for the performance and safety of lithium-ion batteries are increasing. Lithium cells are the core components of battery pack safety and assembly, and their structural design is crucial to cell safety.

[0003] Existing battery cells usually use a plastic structure under the cover to fix the battery cell pole group. However, the pole group is not fixed sufficiently and is prone to movement. Utility Model Content

[0004] In view of this, the utility model provides a battery cell structure and a battery to solve the problem that the existing battery cell electrode group is not sufficiently fixed and the electrode group is prone to movement.

[0005] In a first aspect, the utility model provides a battery cell structure, comprising:

[0006] A shell, the inner wall of which encloses a receiving cavity;

[0007] The pole group is built into the accommodation cavity;

[0008] A cover plate assembly is arranged on one side of the housing along the first direction, and the cover plate assembly is suitable for fixing the electrode group in the accommodation cavity;

[0009] The pad is arranged between the pole group and the cover plate assembly. One side of the pad along its own thickness direction is in contact with the pole group, and the other side is in contact with the cover plate assembly.

[0010] Beneficial effect: The battery cell structure provided by the utility model arranges a pad between the pole group and the cover plate assembly. When the cover plate assemblies on both sides of the battery cell push the pole group into the shell, one side of the pad along its own thickness direction fits with the pole group, and the other side abuts against the cover plate assembly. The thrust of the cover plate assembly directly acts on the pad, thereby pushing the pole group into the shell through the pad and abutting the pole group through the pad. This not only makes the pole group more evenly stressed and reduces the risk of pole piece damage and tearing, but also can fully fix the pole group and avoid the pole group from moving.

[0011] In an optional implementation, the thickness of the pad is L, and L satisfies 0.3 mm ≤ L ≤ 2 mm.

[0012] Beneficial effect: The thickness L of the pad satisfies 0.3mm≤L≤2mm, which can not only ensure sufficient structural strength of the pad and avoid deformation of the pad during assembly, thereby effectively avoiding the risk of pole group movement and pole piece damage, but also limit the space occupied by the pad, thereby ensuring the volume energy density of the battery cell and reducing material costs.

[0013] In an optional embodiment, the battery cell structure further includes a pole ear, which is arranged on one side of the pole group close to the cover plate assembly along the first direction;

[0014] The pad is provided with avoidance holes corresponding to the pole lugs, and the avoidance holes are suitable for avoiding the pole lugs.

[0015] Beneficial effect: By opening an avoidance hole on the pad, the pole ear is avoided, so that the pole ear is convenient to pass through the avoidance hole during the assembly process, so that the pole ear is electrically connected to the pole on the cover plate assembly; at the same time, in the process of the pole ear passing through the avoidance hole, the pre-positioning between the pad and the pole group is completed. After the pad and the pole group are fitted, it is only necessary to abut the cover plate assembly with the side of the pad away from the pole group, which reduces the number of positioning times during the assembly process and is conducive to automated production.

[0016] In an optional embodiment, the pole ear includes a first connection portion and a second connection portion, the first connection portion is arranged on a side of the pad close to the pole group, the first connection portion is suitable for being electrically connected to the pole group, the second connection portion is suitable for extending from the first connection portion along a first direction toward a direction close to the cover plate assembly and passing through the avoidance hole, and the second connection portion is suitable for being electrically connected to the pole on the cover plate assembly;

[0017] The pad is made of insulating material and is suitable for insulating the first connecting portion and the second connecting portion.

[0018] Beneficial effects: The pad is made of insulating material, and the first connecting part is arranged on the side of the pad close to the pole group. During the assembly process, the second connecting part extends from the first connecting part along the first direction toward the cover plate assembly and passes through the avoidance hole, so that the second connecting part is arranged on the side of the pad away from the pole group, avoiding the overlap of the second connecting part and the first connecting part, thereby preventing internal short circuit of the battery cell and avoiding the risk of thermal reaction.

[0019] In an optional embodiment, the battery cell structure also includes an insulating film, which is coated on the outer wall of the pole group and extends to the cover plate assembly on both sides along the first direction. The insulating film is suitable for insulating between the shell and the pole group and between the shell and the pole ear.

[0020] Beneficial effect: thus preventing overlap between the shell and the pole group and / or between the shell and the pole ear, avoiding internal short circuit of the battery cell.

[0021] In an optional embodiment, the backing plate is made of an elastic material, one side of the backing plate along its own thickness direction is in contact with the pole group, and the other side is suitable for elastically abutting against the cover plate assembly.

[0022] Beneficial effect: This prevents the pad from plastic deformation and damage, thereby effectively avoiding the risk of pole group movement and pole piece damage.

[0023] In an optional embodiment, the cover plate assembly includes:

[0024] A first plate body, the first plate body is suitable for welding with the shell;

[0025] A first insulating member is disposed on one side of the first plate body close to the pole group along the first direction;

[0026] The end plate is arranged on a side of the first insulating member away from the first plate body, one side of the end plate along the first direction abuts against the first insulating member, and the other side of the end plate is suitable for abutting against the pad.

[0027] Beneficial effect: One side of the pad along its own thickness direction is in contact with the pole group, and the other side is in contact with the end plate. The thrust of the cover plate assembly acts on the pad through the end plate, thereby pushing the pole group into the shell through the pad and supporting the pole group through the pad, so that the force on the pole group is more uniform, which not only reduces the risk of damage to the pole piece, but also can fully fix the pole group.

[0028] In an optional embodiment, the end plate includes a first side wall and a second side wall arranged relatively spaced apart along a second direction, and a limiting portion extending from a side edge of the first side wall away from the first insulating member along the second direction toward a direction close to the second side wall, wherein the limiting portion is suitable for limiting the pole ear.

[0029] Beneficial effect: When the cover plate assembly pushes the pole group into the shell, the limiting part of the end plate limits the pole ear, so that the pole ear changes from a pre-bent shape to a set bent shape, which not only prevents the second connecting part of the pole ear from overlapping with the first connecting part, but also prevents the pole ear from overlapping with the inner wall of the shell, thereby avoiding internal short circuit of the battery cell.

[0030] In an optional embodiment, the cover plate assembly includes:

[0031] A second plate body, the second plate body is suitable for welding with the shell;

[0032] The second insulating member has one side along the first direction abutting against the second plate body, and the other side thereof is suitable for abutting against the pad.

[0033] Beneficial effect: One side of the pad along its own thickness direction is in contact with the pole group, and the other side is in contact with the second insulating member. The thrust of the cover plate assembly acts on the pad through the second insulating member, thereby pushing the pole group into the shell through the pad and supporting the pole group through the pad, so that the pole group is subjected to more uniform force, which not only reduces the risk of damage to the pole piece, but also can fully fix the pole group.

[0034] In a second aspect, the utility model further provides a battery, comprising: a battery body, and the battery cell structure as described above.

[0035] Beneficial effects: The battery of the second aspect includes the battery cell structure of the first aspect, and therefore, the battery of the second aspect includes all the beneficial effects of the battery cell structure of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 It is a schematic diagram of the assembly of a battery core structure close to the first plate body of an embodiment of the utility model;

[0038] Figure 2 This is a front view of a backing plate of a battery core structure according to an embodiment of the utility model;

[0039] Figure 3 for Figure 1 Schematic diagram of the assembly of the middle electrode group, the backing plate and the electrode ear;

[0040] Figure 4 This is a schematic diagram of the limiting principle of the end plate to the pole ear of a battery cell structure according to an embodiment of the utility model;

[0041] Figure 5 It is an exploded schematic diagram of a battery core structure close to the first plate body of an embodiment of the utility model;

[0042] Figure 6 It is a schematic diagram of the assembly of a battery core structure close to the second plate body of an embodiment of the utility model;

[0043] Figure 7 for Figure 6 Schematic diagram of the assembly of the middle electrode group, the backing plate and the electrode ear;

[0044] Figure 8 It is an exploded schematic diagram of a battery core structure close to the second plate body of an embodiment of the utility model.

[0045] Description of reference numerals:

[0046] 10. housing; 101. accommodating chamber;

[0047] 20. Pole group;

[0048] 30. Cover plate assembly; 31. First plate body; 32. End plate; 321. First side wall; 322. Second side wall; 323. Position limiting portion; 33. First insulating member; 34. Second plate body; 35. Second insulating member;

[0049] 40. pad; 401. avoidance hole;

[0050] 50, tab; 501, first connection portion; 502, second connection portion;

[0051] 60. Insulating film. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0053] Combine the following Figures 1 to 8 , describing an embodiment of the utility model.

[0054] According to an embodiment of the present utility model, on the one hand, a battery cell structure is provided, comprising:

[0055] The housing 10 has an inner wall which encloses a receiving chamber 101;

[0056] The electrode group 20 is built into the accommodation cavity 101;

[0057] The cover plate assembly 30 is disposed on one side of the housing 10 along the first direction, and the cover plate assembly 30 is suitable for fixing the electrode group 20 in the accommodation cavity 101;

[0058] The backing plate 40 is disposed between the electrode group 20 and the cover plate assembly 30 . One side of the backing plate 40 along its thickness direction is in contact with the electrode group 20 , and the other side of the backing plate 40 is in contact with the cover plate assembly 30 .

[0059] It should be noted that the pad 40 can be arranged on the positive electrode side of the battery cell, or on the negative electrode side of the battery cell. The pad 40 can be a sheet structure, thereby simplifying the processing technology and reducing the production cost.

[0060] The battery cell in the related technology usually adopts the plastic structure under the cover to fix the electrode group. The actual force between the electrode group and the plastic under the cover is generated by the diaphragm that constitutes the electrode group. On the one hand, the electrode group diaphragm is very thin and has low strength. The area of ​​the electrode group diaphragm position compressed by the plastic structure under the cover is small, and the force is uneven, which can easily damage the electrode piece. On the other hand, the electrode group diaphragm is easily deformed under pressure, resulting in insufficient fixation of the electrode group and easy movement of the electrode group.

[0061] The battery cell structure provided by the utility model has a pad 40 arranged between the electrode group 20 and the cover plate assembly 30. When the cover plate assemblies 30 on both sides of the battery cell push the electrode group 20 into the shell, one side of the pad 40 along its own thickness direction is in contact with the electrode group 20, and the other side is in contact with the cover plate assembly 30. The thrust of the cover plate assembly 30 directly acts on the pad 40, so that the electrode group 20 is pushed into the shell by the pad 40 and the pole group 20 is abutted by the pad 40. This not only makes the force on the electrode group 20 more uniform and reduces the risk of damage and tearing of the electrode sheet, but also can fully fix the electrode group 20 and avoid the movement of the electrode group 20.

[0062] In some embodiments, the thickness of the backing plate 40 is L, and L satisfies 0.3 mm≤L≤2 mm.

[0063] It should be noted that the pad 40 cannot be too thin, otherwise it will easily lead to insufficient structural strength of the pad 40, causing deformation of the pad 40 during assembly, affecting assembly, therefore, the thickness L of the pad 40 must satisfy L≥0.3mm; the pad 40 cannot be too thick either, otherwise it will easily lead to a large space occupied by the pad 40, reducing the volume energy density of the battery cell, and also easily increasing material costs, therefore, the thickness L of the pad 40 must also satisfy L≤2mm.

[0064] In the battery cell structure provided by the utility model, the thickness L of the pad 40 satisfies 0.3mm≤L≤2mm, which can ensure sufficient structural strength of the pad 40 and avoid deformation of the pad 40 during assembly, thereby effectively avoiding the risk of movement of the electrode group 20 and damage to the electrode piece, and can limit the space occupied by the pad 40, thereby ensuring the volume energy density of the battery cell and reducing material costs.

[0065] In some embodiments, see Figure 1 and Figure 6 As shown, the battery cell structure further includes a pole ear 50, which is disposed on one side of the pole group 20 close to the cover plate assembly 30 along the first direction;

[0066] Please combine Figure 2 As shown, a avoidance hole 401 corresponding to the pole lug 50 is opened on the pad 40 , and the avoidance hole 401 is suitable for avoiding the pole lug 50 .

[0067] It should be noted that the shape of the avoidance hole 401 can be adjusted according to the specific structural shape of the connection part between the pole ear 50 and the pole group 20, and is not limited to Figure 1 and Figure 2 The shapes shown in .

[0068] The battery cells in the related art usually use a plastic structure under the cover to fix the electrode group. The actual force between the electrode group and the plastic under the cover is generated by the diaphragm that constitutes the electrode group. This structure also has the problem of complex parts structure design and multiple positioning required for assembly, which is not conducive to automated production.

[0069] In this embodiment, an avoidance hole 401 is opened on the pad 40 to avoid the pole ear 50, so that the pole ear 50 can pass through the avoidance hole 401 during the assembly process, so that the pole ear 50 is electrically connected to the pole on the cover plate assembly 30; at the same time, in the process of the pole ear 50 passing through the avoidance hole 401, the pre-positioning between the pad 40 and the pole group 20 is completed. After the pad 40 is fitted with the pole group 20, it is only necessary to abut the cover plate assembly 30 against the side of the pad 40 away from the pole group 20, thereby reducing the number of positioning times during the assembly process and facilitating automated production.

[0070] In some embodiments, please combine Figure 1 and Figure 3 as well as Figure 6 and Figure 7 As shown, the pole ear 50 includes a first connection portion 501 and a second connection portion 502, the first connection portion 501 is arranged on a side of the pad 40 close to the pole group 20, the first connection portion 501 is suitable for being electrically connected to the pole group 20, the second connection portion 502 is suitable for extending from the first connection portion 501 along a first direction toward the direction close to the cover plate assembly 30 and passing through the avoidance hole 401, and the second connection portion 502 is suitable for being electrically connected to the pole on the cover plate assembly 30;

[0071] The pad 40 is made of an insulating material, and is suitable for insulating the first connection portion 501 and the second connection portion 502 .

[0072] Furthermore, the pad 40 may be made of plastic.

[0073] In this embodiment, the pad 40 is made of an insulating material, and the first connecting portion 501 is arranged on a side of the pad 40 close to the pole group 20. During the assembly process, the second connecting portion 502 extends from the first connecting portion 501 along the first direction toward the cover plate assembly 30 and passes through the avoidance hole 401, so that the second connecting portion 502 is arranged on a side of the pad 40 away from the pole group 20, avoiding overlap between the second connecting portion 502 and the first connecting portion 501, thereby preventing internal short circuit of the battery cell and avoiding the risk of thermal reaction.

[0074] In some embodiments, see Figure 1 and Figure 6 As shown, the battery cell structure also includes an insulating film 60, which is coated on the outer wall of the pole group 20, and the insulating film 60 extends to the cover plate assembly 30 on both sides along the first direction. The insulating film 60 insulates the shell 10 and the pole group 20 and the shell 10 and the pole ear 50, thereby preventing overlap between the shell 10 and the pole group 20 and / or between the shell 10 and the pole ear 50, thereby avoiding internal short circuit of the battery cell.

[0075] In some embodiments, the pad 40 is made of an elastic material, and one side of the pad 40 along its own thickness direction is in contact with the pole group 20, and the other side is suitable for elastically abutting against the cover plate assembly 30, thereby preventing the pad 40 from undergoing plastic deformation and avoiding damage to the pad 40, thereby effectively avoiding the risk of movement of the pole group 20 and damage to the pole piece.

[0076] In some embodiments, please combine Figure 1 and Figure 5 As shown, the cover assembly 30 includes:

[0077] A first plate body 31, the first plate body 31 is suitable for welding with the housing 10;

[0078] A first insulating member 33 is disposed on one side of the first plate 31 close to the pole group 20 along the first direction;

[0079] The end plate 32 is disposed on a side of the first insulating member 33 away from the first plate body 31 . One side of the end plate 32 along the first direction abuts against the first insulating member 33 , and the other side of the end plate 32 is suitable for abutting against the pad 40 .

[0080] Furthermore, the first insulating member 33 may be made of plastic.

[0081] In this embodiment, one side of the pad 40 along its own thickness direction is in contact with the pole group 20, and the other side is in contact with the end plate 32. The thrust of the cover plate assembly 30 acts on the pad 40 through the end plate 32, thereby pushing the pole group 20 into the shell through the pad 40 and abutting the pole group 20 through the pad 40, so that the pole group 20 is subjected to more uniform force, which not only reduces the risk of damage to the pole piece, but also can fully fix the pole group 20.

[0082] In some embodiments, see Figure 4 As shown, the end plate 32 includes a first side wall 321 and a second side wall 322 that are relatively spaced apart along the second direction, and a limiting portion 323 extending from a side edge of the first side wall 321 away from the first insulating member 33 along the second direction toward the second side wall 322, and the limiting portion 323 is suitable for limiting the pole ear 50.

[0083] It should be noted that in the process, please refer to Figure 3As shown, after the tab 50 passes through the avoidance hole 401 of the pad 40, the tab 50 is pre-bent to form an "S"-shaped structure, see Figure 4 As shown, when the cover plate assembly 30 pushes the pole group 20 into the shell, the limiting portion 323 of the end plate 32 limits the pole ear 50, so that the pole ear 50 changes from a pre-bent shape to a set bent shape, which not only prevents the second connection portion 502 of the pole ear 50 from overlapping with the first connection portion 501, but also prevents the pole ear 50 from overlapping with the inner wall of the shell 10, thereby avoiding internal short circuit of the battery cell.

[0084] Furthermore, the limiting portion 323 and the first side wall 321 are arranged at an angle.

[0085] In some embodiments, please combine Figure 6 and Figure 8 As shown, the cover assembly 30 includes:

[0086] A second plate 34, the second plate 34 is suitable for welding with the housing 10;

[0087] The second insulating member 35 has one side along the first direction abutting against the second plate body 34 , and the other side thereof is suitable for abutting against the pad 40 .

[0088] Furthermore, the second insulating member 35 may be made of plastic.

[0089] In this embodiment, one side of the pad 40 along its own thickness direction is in contact with the pole group 20, and the other side is in contact with the second insulating member 35. The thrust of the cover plate assembly 30 acts on the pad 40 through the second insulating member 35, thereby pushing the pole group 20 into the shell through the pad 40 and abutting the pole group 20 through the pad 40, so that the pole group 20 is subjected to more uniform force, which not only reduces the risk of damage to the pole piece, but also can fully fix the pole group 20.

[0090] According to an embodiment of the present invention, on the other hand, a battery is provided, including: a battery body, and the battery cell structure as described above.

[0091] The battery in this embodiment includes the above-mentioned battery cell structure, and therefore, the battery in this embodiment includes all the beneficial effects of the above-mentioned battery cell structure.

[0092] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A battery cell structure, characterized in that: include: A shell, the inner wall of which encloses a receiving cavity; A pole group, built into the accommodating cavity; A cover plate assembly, disposed on one side of the housing along the first direction, the cover plate assembly being suitable for fixing the electrode group in the accommodating cavity; The backing plate is arranged between the pole group and the cover plate assembly. One side of the backing plate along its own thickness direction is in contact with the pole group, and the other side is in contact with the cover plate assembly.

2. The battery cell structure according to claim 1, characterized in that: The thickness of the pad is L, and L satisfies 0.3mm≤L≤2mm.

3. The battery cell structure according to claim 1, characterized in that: The battery cell structure further includes a pole ear, which is arranged on a side of the pole group close to the cover plate assembly along the first direction; The pad is provided with an avoidance hole corresponding to the pole lug, and the avoidance hole is suitable for avoiding the pole lug.

4. The battery cell structure according to claim 3, characterized in that: The pole ear comprises a first connection portion and a second connection portion, wherein the first connection portion is arranged on a side of the pad close to the pole group, the first connection portion is suitable for being electrically connected to the pole group, and the second connection portion is suitable for extending from the first connection portion along a first direction toward a direction close to the cover plate assembly and passing through the avoidance hole, and the second connection portion is suitable for being electrically connected to the pole on the cover plate assembly; The pad is made of an insulating material and is suitable for insulating the first connecting portion and the second connecting portion.

5. The battery cell structure according to claim 3, characterized in that: The battery cell structure also includes an insulating film, which is coated on the outer wall of the pole group and extends to the cover plate assembly on both sides along the first direction. The insulating film is suitable for insulating between the shell and the pole group and between the shell and the pole ear.

6. The battery cell structure according to claim 1, characterized in that: The pad is made of an elastic material, one side of the pad along its own thickness direction is in contact with the pole group, and the other side is suitable for elastically abutting against the cover plate assembly.

7. The battery core structure according to any one of claims 3 to 5, characterized in that: The cover plate assembly comprises: A first plate body, wherein the first plate body is suitable for being welded to the shell; A first insulating member, disposed on one side of the first plate body close to the pole group along a first direction; The end plate is arranged on a side of the first insulating member away from the first plate body, one side of the end plate along the first direction abuts against the first insulating member, and the other side of the end plate is suitable for abutting against the pad.

8. The battery cell structure according to claim 7, characterized in that: The end plate includes a first side wall and a second side wall spaced apart from each other along a second direction, and a limiting portion extending from an edge of the first side wall away from the first insulating member along the second direction toward the second side wall, wherein the limiting portion is suitable for limiting the pole ear.

9. The battery core structure according to any one of claims 1 to 6, characterized in that: The cover plate assembly comprises: a second plate body, the second plate body being suitable for being welded to the shell; The second insulating member has one side along the first direction abutting against the second plate body, and the other side thereof is suitable for abutting against the pad.

10. A battery, characterized in that: include: A battery body, and a battery core structure as claimed in any one of claims 1 to 9.

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