Battery monomer, battery module and battery pack

Abstract

The invention belongs to the technical field of batteries, and discloses a battery monomer, a battery module and a battery pack, the battery monomer comprises a shell and a unit structure, the shell comprises a plurality of wall bodies, the plurality of wall bodies are sequentially connected end to end to define a containing cavity, one of the plurality of wall bodies is a first wall body, a welding seam is arranged on the first wall body, and the other wall body is a second wall body. The size of the welding seam protruding out of the surface of the side, facing the containing cavity, of the first wall body is H1, the wall body opposite to the first wall body is a second wall body, the pole group structure is arranged in the containing cavity, the distance between the pole group structure and the surface of the side, facing the containing cavity, of the first wall body is L1, the distance between the pole group structure and the surface of the side, facing the containing cavity, of the second wall body is L2, and (L1 + L2) / H1 is larger than or equal to 8.9. According to the design, side plates can be omitted, and the effects of reducing the material cost, reducing the process difficulty and improving the production efficiency are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery cell, a battery module and a battery pack. Background Art

[0002] As Figure 1 shown, the existing blade battery includes components such as a housing 1 and a pole group 2. Among them, the housing 1 is made of a sheet material through bending and welding processes. Specifically, after the sheet material is bent several times, the two side edges of the sheet material are overlapped, and the overlapped area of the sheet material is welded to form a weld seam 3, so that the two side edges of the sheet material are fixed through the weld seam 3, thereby forming a housing 1 with an open cavity.

[0003] When the pole group 2 is inserted into the housing 1 from the opening of the housing 1, since the weld seam 3 protrudes from the inner surface of the housing 1, the problem that the weld seam 3 scratches the pole group 2 easily occurs, and further damages the pole group 2. To solve this technical problem, a side plate 4 is often provided on the side of the pole group 2 facing the weld seam 3, and the pole group 2 is separated from the weld seam 3 through the side plate 4 to prevent the weld seam 3 from scratching the pole group 2. However, the above technical solution increases the components of the blade battery, not only increasing the material cost, but also increasing the process difficulty and reducing the production efficiency.

[0004] Therefore, there is an urgent need to propose a battery cell, a battery module and a battery pack to solve the above technical problems. Summary of the Invention

[0005] The first object of the present invention is to provide a battery cell, which can eliminate the side plate, achieving the effects of reducing material cost, reducing process difficulty and improving production efficiency.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] A battery cell, comprising:

[0008] A housing, the housing includes a plurality of wall bodies, the plurality of wall bodies are sequentially connected end to end to enclose a receiving cavity, one of the plurality of wall bodies is a first wall body, a weld seam is provided on the first wall body, and the size of the weld seam protruding from the surface of the first wall body facing the receiving cavity is H1, and the wall body opposite to the first wall body is a second wall body;

[0009] A pole group structure, the pole group structure is arranged in the receiving cavity, the distance between the pole group structure and the surface of the first wall body facing the receiving cavity is L1, the distance between the pole group structure and the surface of the second wall body facing the receiving cavity is L2, and (L1 + L2) / H1 ≥ 8.9.

[0010] Optionally, the electrode group structure includes an electrode group and an insulating film. The insulating film includes a main body portion and an edge portion connected to each other. The main body portion wraps around the outer peripheral wall of the electrode group. The edge portion is stacked on one side of the main body portion away from the edge portion. The edge portion faces the weld seam, and the extending directions of the main body portion, the edge portion, and the weld seam are the same.

[0011] Optionally, L1 is the distance between the main body portion facing the first wall body and the surface of the first wall body facing the accommodation cavity.

[0012] Optionally, the thicknesses of both the main body portion and the edge portion are T1, and T1≥0.08mm.

[0013] Optionally, (L1 + L2) / H1≤45.

[0014] Optionally, 0.02mm≤H1≤0.2mm.

[0015] Optionally, 0.4mm≤L1≤0.8mm.

[0016] Optionally, 0.4mm≤L2≤0.8mm.

[0017] The second object of the present invention is to provide a battery module, which has a low production cost, low process difficulty, and high production efficiency.

[0018] To achieve this purpose, the present invention adopts the following technical solutions:

[0019] The battery module includes the above-mentioned battery cell.

[0020] The third object of the present invention is to provide a battery pack, which has a low production cost, low process difficulty, and high production efficiency.

[0021] To achieve this purpose, the present invention adopts the following technical solutions:

[0022] The battery pack includes a box body and the above-mentioned battery module, and the battery module is arranged in the box body.

[0023] The beneficial effects of the present invention:

[0024] For the battery cell provided by the present invention, the dimension of the weld protruding from the surface of the first wall towards the accommodation cavity (hereinafter referred to as the inner surface of the first wall) is H1, the distance between the pole group structure and the inner surface of the first wall is L1, and the distance between the pole group structure and the surface of the second wall towards the accommodation cavity (hereinafter referred to as the inner surface of the second wall) is L2, and (L1 + L2) / H1 ≥ 8.9, ensuring that L1 + L2 is much larger than H1. Furthermore, the distance between the pole group structure and the weld can be increased. When the pole group structure is installed into the accommodation cavity, the probability of the weld rubbing against the pole group structure can be significantly reduced. Furthermore, the side plate can be omitted, achieving the effects of reducing material costs, reducing process difficulty, and improving production efficiency. Description of the Drawings

[0025] Figure 1 is a schematic diagram of the partial explosion structure of a blade battery in the prior art;

[0026] Figure 2 is a schematic diagram of the first explosion structure of the battery cell provided by the present invention;

[0027] Figure 3 is Figure 2 the cross-sectional view taken along the E-E direction in

[0028] Figure 4 is Figure 3 the partial enlarged view at A in

[0029] Figure 5 is Figure 3 the partial enlarged view at B in

[0030] Figure 6 is a schematic diagram of the second explosion structure of the battery cell provided by the present invention;

[0031] Figure 7 is a schematic diagram of the first structure of the insulating film provided by the present invention;

[0032] Figure 8 is a schematic diagram of the second structure of the insulating film provided by the present invention.

[0033] In the figure:

[0034] 1. Housing; 2. Pole group; 3. Weld; 4. Side plate;

[0035] 100. Housing; 110. Accommodation cavity; 120. First wall; 130. Second wall; 200. Weld; 300. Pole group structure; 310. Pole group; 320. Insulating film; 321. Main body part; 322. Edge part. Detailed Embodiments

[0036] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that, for the sake of description, only the parts related to the present invention are shown in the drawings, rather than all the structures.

[0037] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected", and "fixed" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral body; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0038] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over", and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "under", and "beneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or simply means that the horizontal height of the first feature is lower than that of the second feature.

[0039] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "right", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for distinction in description and have no special meanings.

[0040] This embodiment provides a battery cell, which can omit the side plate, achieving the effects of reducing material costs, reducing process difficulties, and improving production efficiency.

[0041] Specifically, as Figures 2 to 6As shown, the battery cell includes a housing 100 and a pole group structure 300. Among them, the housing 100 includes a plurality of wall bodies. The plurality of wall bodies are sequentially connected end to end to enclose an accommodation cavity 110. One of the plurality of wall bodies is a first wall body 120. A weld 200 is provided on the first wall body 120. The size of the weld 200 protruding from the surface of the first wall body 120 facing the accommodation cavity 110 is H1. The wall body opposite to the first wall body 120 is a second wall body 130. The pole group structure 300 is arranged in the accommodation cavity 110. The distance between the pole group structure 300 and the surface of the first wall body 120 facing the accommodation cavity 110 is L1. The distance between the pole group structure 300 and the surface of the second wall body 130 facing the accommodation cavity 110 is L2. (L1 + L2) / H1 ≥ 8.9. Exemplarily, (L1 + L2) / H1 can be 8.9, 9.0, 9.3, 10.8, 22 or 30, etc. Among them, it is preferably (L1 + L2) / H1 ≥ 9.3.

[0042] Based on the above design, the size of the weld 200 protruding from the surface of the first wall body 120 facing the accommodation cavity 110 (hereinafter referred to as the inner surface of the first wall body 120) is H1. The distance between the pole group structure 300 and the inner surface of the first wall body 120 is L1. The distance between the pole group structure 300 and the surface of the second wall body 130 facing the accommodation cavity 110 (hereinafter referred to as the inner surface of the second wall body 130) is L2. (L1 + L2) / H1 ≥ 8.9, ensuring that L1 + L2 is much larger than H1. Furthermore, the distance between the pole group structure 300 and the weld 200 can be increased. When the pole group structure 300 is installed in the accommodation cavity 110, the probability of the weld 200 rubbing against the pole group structure 300 can be significantly reduced. Furthermore, the side plate can be omitted, achieving the effects of reducing material costs, reducing process difficulties, and improving production efficiency. In addition, since the distance between the pole group structure 300 and the weld 200 is large enough, the probability of the weld 200 rubbing against the pole group structure 300 can also be reduced during the transportation and use of the battery cell, improving the stability of the battery cell. In addition, after omitting the side plate, the problem of side plate hot melting can be avoided, which is beneficial to improving the stability of the battery cell.

[0043] Optionally, to control the size of H1 and reduce the production difficulty, it is necessary to make (L1 + L2) / H1 ≤ 45. Exemplarily, (L1 + L2) / H1 can be 45, 40, 35, 30, or 26, etc. Among them, it is better that (L1 + L2) / H1 ≤ 35. Specifically, in actual production, after the weld 200 is formed on the first wall 120, a scraper is needed to scrape the weld 200 to make it thinner, so as to control H1 within a suitable range. If (L1 + L2) / H1 > 45, H1 will be too small. Since H1 is the size of the weld 200 protruding from the inner surface of the first wall 120, it is necessary to scrape the weld 200 inside the housing 100 to make H1 reach a suitable size. If H1 is too small, the operation difficulty of scraping the weld 200 will be greatly increased and the scraping accuracy will be reduced, thereby increasing the production cost of the housing 100 and the scraping yield of the weld 200. Therefore, controlling (L1 + L2) / H1 below 45 can reduce the operation difficulty of scraping the weld 200, thereby achieving the effects of improving production efficiency and reducing production cost, and can also improve the scraping yield of the weld 200, thereby improving the process yield of the housing 100. And if the scraping accuracy of the weld 200 is to be improved, it is necessary to increase the penetration depth of the weld 200, and then it is necessary to increase the thickness of the first wall 120 to correspond to the larger penetration depth. For example, when H1 is less than 0.03 mm, the thickness of the first wall 120 needs to reach more than 0.4 mm, which will greatly increase the weight and volume of the first wall 120, and then increase the weight and volume of the housing 100, which is not conducive to improving the energy density of the battery cell.

[0044] In this embodiment, (L1 + L2) / H1 ≥ 8.9 and (L1 + L2) / H1 ≤ 45. In other implementation schemes, either (L1 + L2) / H1 ≥ 8.9 or (L1 + L2) / H1 ≤ 45 can also be selected.

[0045] Optionally, 0.02 mm ≤ H1 ≤ 0.2 mm. Exemplarily, H1 can be 0.02 mm, 0.03 mm, 0.05 mm, 0.1 mm, 0.15 mm, or 0.2 mm, etc. Among them, 0.03 mm ≤ H1 ≤ 0.15 mm is preferred. When H1 is less than 0.02 mm, the operation difficulty of scraping the weld 200 will be significantly increased, the scraping accuracy will be reduced, and the thickness of the first wall 120 will be increased, thereby increasing the production cost of the housing 100, reducing the yield rate of the housing 100, and increasing the weight and volume of the housing 100. When H1 > 0.2 mm, the distance between the electrode group structure 300 and the weld 200 will be reduced. Therefore, when the electrode group structure 300 is installed in the accommodation cavity 110, during transportation and use of the battery cell, the probability of the weld 200 rubbing against the electrode group structure 300 will be significantly increased. Therefore, controlling H1 between 0.02 mm and 0.2 mm can not only reduce the operation difficulty of scraping the weld 200, but also ensure that there is a sufficient distance between the weld 200 and the electrode group 310.

[0046] Optionally, 0.4 mm ≤ L1 ≤ 0.8 mm. Exemplarily, L1 can be 0.4 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.7 mm, or 0.8 mm, etc. Among them, 0.5 mm ≤ L1 ≤ 0.7 mm is preferred, which provides further guarantee for having a sufficient distance between the electrode group structure 300 and the weld 200.

[0047] Optionally, 0.4 mm ≤ L2 ≤ 0.8 mm. Exemplarily, L2 can be 0.4 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.7 mm, or 0.8 mm, etc. Among them, 0.5 mm ≤ L2 ≤ 0.7 mm is preferred, ensuring that there is a sufficient distance between the electrode group structure 300 and the inner surface of the second wall 130, and avoiding the problem of the inner surface of the second wall 130 rubbing against the electrode group 310.

[0048] Optionally, the thickness of all walls is W, W ≥ 0.3 mm. Exemplarily, W can be 0.3 mm, 0.35 mm, 0.5 mm, or 0.6 mm, etc., so that the walls have a certain structural strength and reduce the probability of the walls deforming.

[0049] Optionally, as Figure 2 , Figure 4 , Figure 6 , Figure 7 and Figure 8As shown, the electrode group structure 300 includes an electrode group 310 and an insulating film 320, the insulating film 320 includes a main body 321 and an edge portion 322 connected to each other, the main body 321 is coated on the outer peripheral wall of the electrode group 310, the edge portion 322 is stacked with the side of the main body 321 away from the edge portion 322, the edge portion 322 is located on the side of the main body 321 away from the electrode group 310, the edge portion 322 is arranged opposite to the weld 200, and the main body 321, the edge portion 322 and the weld 200 have the same extension direction, as shown in FIG. Figures 6 to 8 As shown, the main body 321 is wrapped around the outer wall of the pole group 310 with an axis parallel to the x-direction as the rotation axis, and the starting area where the main body 321 is wrapped around the pole group 310 is covered by the edge portion 322. The main body 321, the edge portion 322 and the weld 200 all extend along the x-direction. The structural design is provided with a layer of edge portion 322 and a layer of main body 321 at the position where the pole group 310 is opposite to the weld 200, thereby improving the protection effect on the pole group 310 and reducing the probability of the weld 200 scratching the pole group 310 and the probability of insulation failure of the pole group structure 300.

[0050] Further, L2 is the distance between the main body 321 and the surface of the second wall 130 facing the accommodating cavity 110, and L1 is the distance between the main body 321 facing the first wall 120 and the surface of the first wall 120 facing the accommodating cavity 110. Usually, the width of the edge 322 is narrower, that is, the size of the edge 322 in the y direction is smaller, so considering the distance between the main body 321 facing the first wall 120 and the surface of the first wall 120 facing the accommodating cavity 110 as L1 is conducive to reducing the difficulty of measuring L1. Of course, in other embodiments, L1 can also be the distance between the edge 322 and the surface of the first wall 120 facing the accommodating cavity 110, which can be determined according to actual production needs.

[0051] Optionally, the thickness of the main body 321 and the edge portion 322 are both T1, T1 ≥ 0.08 mm. For example, T1 can be 0.08 mm, 0.09 mm, 0.1 mm, 0.15 mm or 0.2 mm, etc., among which T1 ≥ 0.1 mm is preferred, to ensure that the main body 321 and the edge portion 322 have a high ability to resist external force impact, thereby reducing the probability of the main body 321 and the edge portion 322 being scratched by the weld 200.

[0052] Optionally, the battery cell provided in this embodiment further includes a cover plate and an explosion-proof valve (both the cover plate and the explosion-proof valve are not shown in the figure). Among them, the accommodation cavity 110 is an open cavity, that is, there is an opening on the housing 100. After the electrode group structure 300 is loaded into the accommodation cavity 110 through the opening, the cover plate is sealed at the opening so that the accommodation cavity 110 forms a closed cavity. The explosion-proof valve is not provided on the cover plate, but is provided on the housing 100. Thus, the through hole for installing the explosion-proof valve on the cover plate can be omitted, which improves the structural strength of the cover plate.

[0053]

[0054] Table 1 provides six groups of examples and five groups of comparative examples. The battery cells in the six groups of examples and the five groups of comparative examples are all provided with side plates, and weld seams 200 are provided on the first wall 120. The insulating films 320 are all made of polypropylene (PP) material.

[0055] In Example 1, T1 is 0.1 mm, H1 is 0.05 mm, L1 is 0.5 mm, L2 is 0.5 mm, (L1 + L2) / H1 is 20, W is 0.35 mm, and the helium leak detection of the housing 100 meets the requirements, that is, the sealing performance of the housing 100 meets the production requirements. When the electrode group structure 300 is loaded into the housing 100, no problem of the electrode group 310 and the insulating film 320 being scratched by the weld seam 200 is found, and no problem of the electrode group structure 300 being scratched by the weld seam 200 due to crosstalk in the housing 100 is found. The test yield of the battery cell is greater than 99%.

[0056] In Example 2, T1 is 0.1 mm, H1 is 0.07 mm, L1 is 0.55 mm, L2 is 0.5 mm, (L1 + L2) / H1 is 15, W is 0.35 mm, and the helium leak detection of the housing 100 meets the requirements, that is, the sealing performance of the housing 100 meets the production requirements. When the electrode group structure 300 is loaded into the housing 100, no problem of the electrode group 310 and the insulating film 320 being scratched by the weld seam 200 is found, and no problem of the electrode group structure 300 being scratched by the weld seam 200 due to crosstalk in the housing 100 is found. The test yield of the battery cell is greater than 99%.

[0057] In Example 3, T1 is 0.1 mm, H1 is 0.08 mm, L1 is 0.55 mm, L2 is 0.55 mm, (L1 + L2) / H1 is 13.75, W is 0.35 mm, and the helium leak detection of the housing 100 meets the requirements, that is, the sealing performance of the housing 100 meets the production requirements. When the electrode group structure 300 is loaded into the housing 100, no problem of the electrode group 310 and the insulating film 320 being scratched by the weld seam 200 is found, and no problem of the electrode group structure 300 being scratched by the weld seam 200 due to crosstalk in the housing 100 is found. The test yield of the battery cell is greater than 99%.

[0058] In Example 4, T1 is 0.15 mm, H1 is 0.12 mm, L1 is 0.6 mm, L2 is 0.55 mm, (L1 + L2) / H1 is 9.58, W is 0.35 mm. The helium leak detection of the housing 100 meets the requirements, that is, the sealing performance of the housing 100 meets the production requirements. When the electrode group structure 300 is installed in the housing 100, no problem of the electrode group 310 and the insulating film 320 being scratched by the weld 200 is found. Moreover, no problem of the electrode group structure 300 being scratched by the weld 200 due to its movement in the housing 100 is found. The test yield of the battery cell is greater than 99%.

[0059] In Example 5, T1 is 0.1 mm, H1 is 0.15 mm, L1 is 0.7 mm, L2 is 0.7 mm, (L1 + L2) / H1 is 9.33, W is 0.35 mm. The helium leak detection of the housing 100 meets the requirements, that is, the sealing performance of the housing 100 meets the production requirements. When the electrode group structure 300 is installed in the housing 100, no problem of the electrode group 310 and the insulating film 320 being scratched by the weld 200 is found. Moreover, no problem of the electrode group structure 300 being scratched by the weld 200 due to its movement in the housing 100 is found. The test yield of the battery cell is greater than 99%.

[0060] In Example 6, T1 is 0.1 mm, H1 is 0.04 mm, L1 is 0.7 mm, L2 is 0.7 mm, (L1 + L2) / H1 is 35, W is 0.5 mm. The helium leak detection of the housing 100 meets the requirements, that is, the sealing performance of the housing 100 meets the production requirements. When the electrode group structure 300 is installed in the housing 100, no problem of the electrode group 310 and the insulating film 320 being scratched by the weld 200 is found. Moreover, no problem of the electrode group structure 300 being scratched by the weld 200 due to its movement in the housing 100 is found. The test yield of the battery cell is greater than 99%.

[0061] In Comparative Example 1, T1 is 0.1 mm, H1 is 0.16 mm, L1 is 0.6 mm, L2 is 0.6 mm, (L1 + L2) / H1 is 7.5, W is 0.35 mm. The helium leak detection of the housing 100 meets the requirements, that is, the sealing performance of the housing 100 meets the production requirements. When the electrode group structure 300 is installed in the housing 100, a problem that the insulating film 320 is scratched by the weld 200 is found. The test yield of the battery cell is less than 98%.

[0062] In Comparative Example 2, T1 is 0.1 mm, H1 is 0.18 mm, L1 is 0.7 mm, L2 is 0.7 mm, (L1 + L2) / H1 is 7.78, W is 0.35 mm. The helium leak detection of the housing 100 meets the requirements, that is, the sealing performance of the housing 100 meets the production requirements. When the electrode group structure 300 is installed in the housing 100, a problem that the insulating film 320 is scratched by the weld 200 is found. The test yield of the battery cell is less than 98%.

[0063] In Comparative Example 3, T1 is 0.1 mm, H1 is 0.2 mm, L1 is 0.7 mm, L2 is 0.7 mm, (L1 + L2) / H1 is 7, W is 0.35 mm, and the helium leak detection of the housing 100 meets the requirements, that is, the sealing performance of the housing 100 meets the production requirements. When the electrode group structure 300 is installed in the housing 100, it is found that the insulating film 320 is scratched by the weld 200, and the test yield of the battery cell is less than 98%.

[0064] In Comparative Example 4, T1 is 0.1 mm, H1 is 0.16 mm, L1 is 0.7 mm, L2 is 0.7 mm, (L1 + L2) / H1 is 8.75, W is 0.35 mm, and the helium leak detection of the housing 100 meets the requirements, that is, the sealing performance of the housing 100 meets the production requirements. When the electrode group structure 300 is installed in the housing 100, it is found that the insulating film 320 is scratched by the weld 200, and the test yield of the battery cell is less than 98%.

[0065] In Comparative Example 5, T1 is 0.1 mm, H1 is 0.03 mm, L1 is 0.7 mm, L2 is 0.7 mm, (L1 + L2) / H1 is 46.67, W is 0.5 mm, and the helium leak detection of the housing 100 meets the requirements, that is, the sealing performance of the housing 100 meets the production requirements. When the electrode group structure 300 is installed in the housing 100, it is not found that the electrode group 310 and the insulating film 320 are scratched by the weld 200, and moreover, it is not found that the electrode group structure 300 is scratched by the weld 200 due to its movement in the housing 100. The test yield of the battery cell is greater than 99%. However, due to the too small H1, the scraping difficulty of the weld 200 is increased and the flatness of the weld 200 protruding from the inner surface of the first wall 120 is reduced, thereby reducing the scraping yield of the weld 200. If the scraping yield of the weld 200 is to be improved, the process difficulty and cost need to be increased, and even the thickness of the first wall 120 needs to be increased to more than 0.4 mm, resulting in the problems of increased weight and volume of the housing 100, which is not conducive to improving the energy density of the battery cell.

[0066] In summary, when 8.9 ≤ (L1 + L2) / H1 ≤ 45, it is possible to avoid the problem that the insulating film 320 and the electrode group 310 are scratched by the weld 200 on the basis of omitting the side plate, and at the same time, it is possible to reduce the process difficulty of scraping the weld 200 and improve the accuracy of scraping the weld 200 without increasing the thickness of the first wall 120.

[0067] This embodiment also provides a battery module, which includes the above-mentioned battery cell. There is a sufficiently large spacing between the pole group structure 300 of the battery cell and the weld 200 on the housing 100. Therefore, omitting the side plate in the battery cell can also avoid the problem that the weld 200 scratches the pole group structure 300 when the pole group structure 300 is installed in the housing 100, reducing the material cost and process difficulty of the battery cell and improving the production efficiency of the battery cell. The battery module provided in this embodiment also adopts the above-mentioned battery cell, which can reduce the production cost of the battery module and improve the production efficiency of the battery module.

[0068] This embodiment also provides a battery pack, which includes a box body and the above-mentioned battery module. The battery module is arranged in the box body. The battery pack adopts the above-mentioned battery module and has a low production cost, low process difficulty and high production efficiency.

[0069] Obviously, the above-mentioned embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. Battery cell, characterized in that, include: A shell (100), the shell (100) comprising a plurality of wall bodies, the plurality of wall bodies being connected end to end in sequence to enclose a receiving cavity (110), one of the plurality of wall bodies being a first wall body (120), a weld (200) being provided on the first wall body (120), a dimension of the weld (200) protruding from a surface of the first wall body (120) facing the receiving cavity (110) being H1, and the wall body arranged opposite to the first wall body (120) being a second wall body (130); A pole group structure (300), wherein the pole group structure (300) is arranged in the accommodating cavity (110), the distance between the pole group structure (300) and the surface of the first wall (120) facing the accommodating cavity (110) is L1, and the distance between the pole group structure (300) and the surface of the second wall (130) facing the accommodating cavity (110) is L2, and (L1+L2) / H1≥8.

9.

2. The battery cell according to claim 1, characterized in that, The electrode group structure (300) comprises an electrode group (310) and an insulating film (320); the insulating film (320) comprises a main body (321) and an edge portion (322) connected to each other; the main body (321) is coated on the outer peripheral wall of the electrode group (310); the edge portion (322) is stacked with a side of the main body (321) away from the edge portion (322); the edge portion (322) is arranged opposite to the weld (200); and the main body (321), the edge portion (322) and the weld (200) extend in the same direction.

3. The battery cell according to claim 2, characterized in that, L1 is the distance between the main body (321) facing the first wall (120) and the surface of the first wall (120) facing the accommodating cavity (110).

4. The battery cell according to claim 2, wherein The thickness of the main body (321) and the edge (322) are both T1, and T1≥0.08 mm.

5. The battery cell according to any one of claims 1-4, characterized in that, (L1+L2) / H1≤45.

6. The battery cell according to any one of claims 1-4, characterized in that, 0.02mm≤H1≤0.2mm.

7. The battery cell according to any one of claims 1-4, characterized in that, 0.4mm≤L1≤0.8mm.

8. The battery cell according to any one of claims 1-4, characterized in that, 0.4mm≤L2≤0.8mm.

9. Battery module, characterized in that, The invention comprises at least two battery cells according to any one of claims 1 to 8.

10. Battery pack, characterized in that, It comprises a box body and the battery module according to claim 9, wherein the battery module is arranged in the box body.

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