Lithium cell and battery pack

Abstract

The utility model discloses a lithium battery cell and a battery pack, and belongs to the technical field of power batteries. The lithium battery core comprises a shell assembly, a partition plate assembly and two pole groups, the partition plate assembly is fixedly arranged on the shell assembly and divides the shell assembly into two accommodating spaces, and the partition plate assembly comprises a partition plate body and a pressing plate arranged on the partition plate body; the two pole groups are correspondingly arranged in the two containing spaces, the ends, provided with the tabs, of the two pole groups face each other, the tabs of the two pole groups are arranged between the partition plate body and the pressing plate, and the two pole groups are connected in parallel. According to the lithium battery cell and the battery pack, the safety and the reliability of the lithium battery cell and the battery pack are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of power batteries, in particular to a lithium battery cell and a battery pack. Background Art

[0002] Battery packs are widely used in applications such as electric vehicles, requiring high safety standards. As the core component of a battery pack, lithium-ion cells directly impact its safety performance. In related technologies, lithium-ion cells contain an electrode assembly, which consists of a positive electrode sheet, a separator, and a negative electrode sheet stacked or wound in a specific order. Long electrode assembly lengths can lead to problems such as wrinkling, deformation, cross-linking, and fracture of the electrode sheets, compromising the efficiency and quality of electrode assembly manufacturing and potentially causing cell and even battery pack failure or safety issues. Utility Model Content

[0003] The purpose of the utility model is to provide a lithium battery cell and a battery pack to improve the safety and reliability of the lithium battery cell and the battery pack.

[0004] To achieve this purpose, the present invention adopts the following technical solutions:

[0005] A lithium battery cell, comprising:

[0006] housing assembly;

[0007] A partition assembly is fixedly mounted on the shell assembly to separate the shell assembly into two accommodating spaces. The partition assembly includes a partition body and a pressure plate mounted on the partition body.

[0008] Two pole groups are correspondingly arranged in the two accommodating spaces. The ends of the pole ears of the two pole groups are arranged toward each other. The pole ears of the two pole groups are both arranged between the partition body and the pressure plate, and the two pole groups are connected in parallel.

[0009] In some possible embodiments, the electrode group is provided with a first electrode tab and a second electrode tab, the two first electrode tabs and the two second electrode tabs are both provided between the separator body and the pressure plate, the two first electrode tabs are at least partially stacked and welded, and the two second electrode tabs are at least partially stacked and welded.

[0010] In some possible embodiments, the shell assembly includes an outer shell and two side plates disposed in the outer shell, the two side plates are disposed on both sides of the partition assembly, and the two sides of the partition assembly are correspondingly clamped with the two side plates.

[0011] In some possible implementations, the housing assembly further includes two support clamping plates, which are clamped to the two side plates, and the two support clamping plates are arranged on the sides of the two pole groups facing away from each other.

[0012] In some possible implementations, a first explosion-proof valve is provided on a side of the housing facing the side plate; and / or

[0013] The shell assembly further includes two cover plates, which are correspondingly connected to the two ends of the shell, and are arranged corresponding to the two pole groups. The cover plates are provided with a second explosion-proof valve.

[0014] In some possible implementations, the cover plate is a flat plate, and the thickness of the cover plate is L, wherein 1.5 mm < L < 3 mm; and / or

[0015] A convex hump is provided on the outer side of the cover plate, and the height of the convex hump is H, wherein 1.5 mm < H < 3 mm.

[0016] In some possible embodiments, two pressure plates are provided, a limiting groove is provided between the pressure plate and the partition body, the pole group is provided with a first pole tab and a second pole tab, and the two first pole tabs and the two second pole tabs are correspondingly limited in the two limiting grooves.

[0017] In some possible embodiments, the pressure plate is provided with a groove, the groove forming the limiting groove, and the distance between the groove wall facing the side of the partition assembly and the side of the partition assembly is W, wherein 0.25 mm < W < 1.5 mm.

[0018] In some possible implementations, an insulating film is further included, and the two electrode groups are coated on the insulating film.

[0019] A battery pack comprises a box and a plurality of lithium battery cells as described in any one of the above items, wherein the plurality of lithium battery cells are arranged in the box.

[0020] Beneficial effects of the utility model:

[0021] The present invention provides a lithium battery cell and battery pack, in which two electrode groups are connected in parallel to meet energy storage requirements. By arranging the two electrode groups in a split manner, the length of a single electrode group is reduced, and defects such as wrinkles, deformation, layer cross-linking, and fractures caused by the long length of the electrode pieces are reduced, thereby ensuring the manufacturing efficiency and quality of the electrode groups, thereby improving the safety and reliability of the battery cell and battery pack. The partition assembly is fixed to the shell assembly, and as a whole, it plays a role in balancing and fixing the shell assembly and the two electrode groups. The partition body and the pressure plate protect the connection between the electrode ears of the two electrode groups, further improving the safety and reliability of the battery cell and battery pack, and minimizing the length of the electrode ears, reducing the space occupied by the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic diagram of a housing provided by a specific embodiment of the present utility model;

[0023] Figure 2 It is a schematic diagram of a protective patch provided by a specific embodiment of the present utility model;

[0024] Figure 3 This is a partial schematic diagram of a lithium battery cell provided by a specific embodiment of the present utility model;

[0025] Figure 4 It is a schematic diagram of a portion of a housing assembly and a partition assembly provided in a specific embodiment of the present utility model;

[0026] Figure 5 yes Figure 4 Magnified view of point I;

[0027] Figure 6 This is a cross-sectional view of a lithium battery cell at a separator assembly provided by a specific embodiment of the present invention;

[0028] Figure 7 yes Figure 6 Enlarged view of point J;

[0029] Figure 8 is a schematic diagram of a partition assembly provided in a specific embodiment of the present utility model;

[0030] Figure 9 This is a partial schematic diagram of the connection between the partition and the supporting card provided by the specific embodiment of the utility model;

[0031] Figure 10 It is a schematic diagram of a support card provided by a specific embodiment of the present utility model;

[0032] Figure 11 It is a schematic diagram of a cover plate provided in a specific embodiment of the present utility model.

[0033] In the picture:

[0034] 1. Shell assembly; 11. Shell; 12. Side panel; 121. Limiting hole; 122. Limiting stop; 13. Supporting card; 131. Limiting groove; 132. Through hole; 14. First explosion-proof valve; 15. Cover plate; 16. Second explosion-proof valve; 17. Protective sticker; 171. Slit; 18. Bump; 2. Partition assembly; 21. Partition body; 211. Limiting boss; 22. Press plate; 221. Groove; 3. Pole group; 31. First pole ear; 32. Second pole ear; M. Accommodating space. DETAILED DESCRIPTION

[0035] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved more clearly, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work shall fall within the scope of protection of the present invention.

[0036] In the description of this utility model, unless otherwise specified or limited, the terms "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0037] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0038] like Figures 1-11 As shown, this embodiment provides a battery pack, including a case and a plurality of lithium battery cells arranged in the case. This embodiment also provides a lithium battery cell, including a shell assembly 1, a partition assembly 2 and two electrode groups 3. The partition assembly 2 is fixed to the shell assembly 1, dividing the shell assembly 1 into two accommodating spaces M. The partition assembly 2 includes a partition body 21 and a pressure plate 22 arranged on the partition body 21. The two electrode groups 3 are correspondingly arranged in the two accommodating spaces M. The two electrode groups 3 are provided with one end of the pole ears facing each other. The pole ears of the two pole groups 3 are both arranged between the partition body 21 and the pressure plate 22, and the two pole groups 3 are connected in parallel.

[0039] Specifically, the electrode group 3 is provided with a first electrode tab 31 and a second electrode tab 32. The two first electrode tabs 31 and the two second electrode tabs 32 are both provided between the partition body 21 and the pressure plate 22. The two first electrode tabs 31 are connected, and the two second electrode tabs 32 are connected, so that the two electrode groups 3 are connected in parallel to meet the energy storage requirements. By arranging the two electrode groups 3 in a separate manner, the length of a single electrode group 3 is reduced, and the wrinkles, deformation, layer crossover, fracture and other defects caused by the long length of the electrode sheets are reduced, thereby ensuring the manufacturing efficiency and quality of the electrode group 3, thereby improving the safety and reliability of the battery cell and battery pack. The partition assembly 2 is fixed to the shell assembly 1, and as a whole plays a role in balancing and fixing the shell assembly 1 and the two electrode groups 3. The partition body 21 and the pressure plate 22 protect the connection between the electrode tabs of the two electrode groups 3, further improving the safety and reliability of the battery cell and battery pack, and minimizing the length of the electrode tabs and reducing the space occupied by the battery cell.

[0040] The two first pole tabs 31 are at least partially stacked and welded, and the two second pole tabs 32 are at least partially stacked and welded, which has good connection reliability. The pole tabs of the two pole groups 3 are all welded horizontally, which simplifies the process and further reduces the internal resistance.

[0041] Two pressure plates 22 are provided, and a limiting groove is provided between the pressure plate 22 and the partition body 21. The two first pole tabs 31 and the two second pole tabs 32 are correspondingly limited in the two limiting grooves, thereby limiting the two first pole tabs 31 and the two second pole tabs 32 respectively, thereby improving the connection accuracy and reliability. For example, the pressure plate 22 is provided with a groove 221, and the groove 221 forms a limiting groove. The spacing between the groove wall of the groove 221 facing the side of the partition assembly 2 and the side of the partition assembly 2 is W, wherein 0.25mm<W<1.5mm, specifically 0.5mm or 1mm, etc., is not limited. This avoids the size being too small and affecting the structural strength, and also avoids the size being too large and causing the overall size to be too large, thereby increasing the overall volume. In other embodiments, the pressure plate 22 may be provided with a partial groove and the partition body 21 may be provided with a partial groove to form a limiting groove together, or the pressure plate 22 may be a flat plate structure and the partition body 21 may be provided with a groove to form a limiting groove together, and the spacing between the groove wall and the side of the partition assembly 2 may be 0.5 mm or 1 mm, etc.

[0042] Optionally, the partition body 21 and the two pressure plates 22 are integrally formed, and the two pressure plates 22 are connected to both ends of the partition body 21. The pressure plates 22 can be flipped relative to the partition body 21. The pressure plates 22 are opened relative to the partition body 21, and the tabs are placed on the partition body 21. Then, the pressure plates 22 are pressed on the partition body 21 to limit the tabs and provide protection for the tab connections.

[0043] The shell assembly 1 includes an outer shell 11 and two side panels 12 arranged in the outer shell 11. The two side panels 12 are arranged on both sides of the partition assembly 2, and the two sides of the partition assembly 2 are correspondingly snapped with the two side panels 12 to achieve a fixed connection between the partition assembly 2 and the side panels 12, and convenient disassembly and assembly. Specifically, the side panels 12 are provided with limiting holes 121, and the partition body 21 is provided with limiting bosses 211. During assembly, the side panels 12 are installed on the partition assembly 2 from both sides, and the limiting bosses 211 are passed through the limiting holes 121 to achieve the snap connection between the side panels 12 and the partition assembly 2. Optionally, the side panels 12 are flat plates to reduce the occupied space, reduce the number of parts, and simplify the assembly process. The side panels 12 can be formed using mature processes such as injection molding.

[0044] The lithium battery cell also includes an insulating film, which covers the two electrode groups 3 and the tabs to prevent short circuits. During assembly, the insulating film is positioned below the side panels 12, which have multiple protrusions. The insulating film has grooves corresponding to the protrusions on the side panels 12 to prevent structural interference and prevent assembly problems. During assembly, the side panels 12 and the insulating film are placed together in the outer casing 11 to protect the electrode groups 3.

[0045] The shell assembly 1 also includes two support clips 13, which are clamped to the two side plates 12. The two support clips 13 are arranged on the side of the two pole groups 3 facing away from each other. Specifically, the two support clips 13 and the two side plates 12 are alternately spaced and arranged to form a rectangular frame. The partition assembly 2 is arranged in the rectangular frame and forms two accommodating spaces M. The pole group 3 is arranged on both sides of the partition assembly 2 and is arranged in the rectangular frame, that is, in the two accommodating spaces M. When the pole group 3 is installed into the shell 11, first, the side plates 12, the support clips 13 and the pole group 3 are assembled. The side plates 12 and the support clips 13 can fix the pole group 3 and prevent the pole group 3 from moving. The structure is safer and the protection effect on the pole group 3 is better. After that, the whole is put into the shell. By setting the support clips 13, it can be ensured that the thrust is balanced when the pole group 3 enters the shell. Exemplarily, limiting grooves 131 are provided at both ends of the supporting card plate 13, and the side panel 12 is inserted into the limiting grooves 131 to achieve clamping, and a limiting stop 122 is provided at the end of the side panel 12, which abuts against the outer side of the supporting card plate 13, further achieving structural limitation and installation stability.

[0046] The shell assembly 1 also includes two cover plates 15, and the two cover plates 15 are connected to the two ends of the shell 11 respectively. The two cover plates 15 are arranged corresponding to the two pole groups 3. The two ends of the shell 11 are open, and the two cover plates 15 are installed correspondingly at the two open places. During assembly, the internal structure such as the pole group 3 is installed on the shell 11, and then the two cover plates 15 are installed corresponding to the two support card plates 13. Alternatively, one cover plate 15 can be installed on the shell 11 first, and then the internal structure such as the pole group 3 is installed on the shell 11, and finally the other cover plate 15 is installed on the shell 11. The installation steps are not limited. The two cover plates 15 are respectively the positive cover plate and the negative cover plate, and both are made of plain aluminum plates, with high space utilization rate and low cost. At the same time, because the support card plate 13 is provided between the cover plate 15 and the pole group 3, short circuit is prevented, thereby improving safety and reliability.

[0047] Lithium batteries are at risk of thermal runaway. A first explosion-proof valve 14 is provided on the side of the casing 11 facing the side panel 12, and a second explosion-proof valve 16 is provided on the cover 15. At the same time, an annular exhaust channel is formed in the battery cell to prevent the gas from being unable to be released quickly due to a long and unsmooth path, thereby further ensuring safety.

[0048] Specifically, the housing 11 can have one, two, or more first explosion-proof valves 14. When one first explosion-proof valve 14 is provided, it is located in the center of the housing 11. When two first explosion-proof valves 14 are provided, they are positioned corresponding to the two electrode groups 3. The housing 11 has a hole, and the first explosion-proof valve 14 is installed in the hole and located outside the housing 11. A protective patch 17 is provided inside the housing 11. The material of the protective patch 17 is not limited to prevent the electrode groups 3 from damaging the explosion-proof valve. The protective patch 17 has a slit 171. The presence of the slit 171, without obstruction, helps increase exhaust efficiency and shorten the airway travel. Gas inside the housing 11 can quickly flow through the internal airway and converge at the first explosion-proof valve 14, thereby improving the safety of the lithium battery cell. Optionally, the side panel 12 has a hole to facilitate exhaust. The cover plate 15 has a second explosion-proof valve 16. The small size of the cover plate 15 facilitates the structural layout of the second explosion-proof valve 16 on the cover plate 15. Second explosion-proof valves 16 are installed on both side covers 15. Gas inside the housing 11 is quickly released through internal airways and converges at the nearest second explosion-proof valve 16, ensuring safety. Similarly, the cover 15 has a hole, and a protective patch 17 is installed on the inside of the cover 15. The second explosion-proof valve 16 is installed in the hole and is located outside the cover 15. Optionally, the support bracket 13 has a through hole 132 to facilitate exhaust through the through hole 132.

[0049] The cover plate 15 is a flat plate with a thickness L, where 1.5 mm < L < 3 mm, specifically 2 mm or 2.5 mm, etc., without limitation. A convex bump 18 is formed on the outside of the cover plate 15, connecting adjacent lithium battery cells via the bump 18. The bump 18 is integrally formed with the cover plate 15 and has a height H, where 1.5 mm < H < 3 mm, specifically 2 mm or 2.5 mm, etc., to avoid oversizing the lithium battery cell, which would otherwise be excessively large, and also to avoid undersizing the cell, which would affect structural reliability.

[0050] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A lithium battery cell, characterized in that: include: Housing assembly (1); A partition assembly (2) is fixedly mounted on the shell assembly (1) to separate the shell assembly (1) into two accommodating spaces (M); the partition assembly (2) comprises a partition body (21) and a pressure plate (22) mounted on the partition body (21); Two pole groups (3) are correspondingly arranged in the two accommodating spaces (M), and the pole ears of the two pole groups (3) are arranged at one end facing each other. The pole ears of the two pole groups (3) are both arranged between the partition body (21) and the pressure plate (22), and the two pole groups (3) are connected in parallel.

2. The lithium battery cell according to claim 1, characterized in that The electrode group (3) is provided with a first electrode tab (31) and a second electrode tab (32); the two first electrode tabs (31) and the two second electrode tabs (32) are both provided between the separator body (21) and the pressure plate (22); the two first electrode tabs (31) are at least partially stacked and welded, and the two second electrode tabs (32) are at least partially stacked and welded.

3. The lithium battery cell according to claim 1, characterized in that The housing assembly (1) comprises an outer shell (11) and two side plates (12) arranged in the outer shell (11); the two side plates (12) are arranged on both sides of the partition assembly (2), and the two sides of the partition assembly (2) are correspondingly engaged with the two side plates (12).

4. The lithium battery cell according to claim 3, characterized in that The housing assembly (1) further comprises two supporting clamping plates (13), the supporting clamping plates (13) being clamped to the two side plates (12), and the two supporting clamping plates (13) being arranged on the sides of the two pole groups (3) facing away from each other.

5. The lithium battery cell according to claim 3, characterized in that A first explosion-proof valve (14) is provided on the side of the housing (11) facing the side plate (12); and / or The housing assembly (1) further comprises two cover plates (15), the two cover plates (15) being connected to the two ends of the housing (11) respectively, the two cover plates (15) being arranged corresponding to the two pole groups (3), and the cover plates (15) being provided with a second explosion-proof valve (16).

6. The lithium battery cell according to claim 5, characterized in that The cover plate (15) is a flat plate, and the thickness of the cover plate (15) is L, wherein 1.5 mm < L < 3 mm; and / or A convex bump (18) is provided on the outer side of the cover plate (15), and the height of the convex bump (18) is H, wherein 1.5 mm < H < 3 mm.

7. The lithium battery cell according to claim 1, characterized in that Two pressing plates (22) are provided, and a limiting groove is provided between the pressing plate (22) and the partition body (21). The pole group (3) is provided with a first pole lug (31) and a second pole lug (32), and the two first pole lugs (31) and the two second pole lugs (32) are correspondingly limited in the two limiting grooves.

8. The lithium battery cell according to claim 7, characterized in that The pressure plate (22) is provided with a groove (221), the groove (221) forming the limiting groove, the spacing between the groove wall of the groove (221) facing the side of the partition assembly (2) and the side of the partition assembly (2) is W, wherein 0.25mm<W<1.5mm.

9. The lithium battery cell according to any one of claims 1 to 8, characterized in that: It also includes an insulating film, and the two pole groups (3) are covered by the insulating film.

10. A battery pack, characterized in that: The invention comprises a box body and a plurality of lithium battery cells according to any one of claims 1 to 9, wherein the plurality of lithium battery cells are arranged in the box body.

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