Battery cell shell and battery cell

Abstract

The invention relates to the technical field of energy storage equipment, in particular to a battery cell shell and a battery cell, and the battery cell shell comprises a shell body and an explosion-proof assembly. Wherein the shell body is provided with a first side wall, and an anti-explosion through hole is formed in the first side wall. The explosion-proof assembly is provided with a weak part, the explosion-proof assembly is riveted to the first side wall so that the explosion-proof assembly can block the explosion-proof through hole, and the position of the weak part on the explosion-proof assembly corresponds to the position of the explosion-proof through hole. The explosion-proof assembly is riveted on the shell body, so that an explosion-proof valve does not need to be directly welded on the shell body, the problem of deformation of the shell body caused by welding can be fundamentally avoided, the pole group is ensured to enter the shell normally, and the yield of a battery cell is improved. The battery cell comprises a battery cell top cover, a pole group and the battery cell shell, the battery cell top cover hermetically covers the opening of the battery cell shell to form a shell of the battery cell, and the pole group is arranged in the shell. According to the battery cell, the battery cell shell can be prevented from being deformed, the pole group is prevented from being scratched when entering the shell, and the yield is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage devices, and particularly to a battery cell housing and a battery cell. Background Art

[0002] To ensure the safety of battery cells during use, explosion-proof valves are generally provided in battery cells. Once a thermal runaway occurs in the battery cell, the explosion-proof valve can release the high-temperature gas inside the battery cell at a fixed point to prevent the battery cell from exploding. In the prior art, the explosion-proof valve is generally arranged on the top cover of the battery cell. However, the top cover of the battery cell is located at one end in the length direction of the battery cell, and the path for the gas to reach the explosion-proof valve is relatively long, which is not conducive to improving the safety of the battery cell. Arranging the explosion-proof valve on the side wall with a smaller area of the battery cell housing can shorten the exhaust path and improve the safety performance. However, the wall thickness of the battery cell housing is smaller than that of the top cover of the battery cell, and in order to arrange the explosion-proof valve, an opening needs to be made on the battery cell housing, and the structural strength at this position will be very weak. Welding the explosion-proof valve easily causes deformation at the adjacent position of the battery cell housing. The deformation is generally an inward concave deformation, which will affect the insertion of the electrode assembly into the housing, cause the electrode assembly to rub against the housing, and affect the yield of the battery cell. Summary of the Invention

[0003] An object of the present invention is to provide a battery cell housing that can avoid deformation, prevent rubbing during the insertion of the electrode assembly into the housing, and improve the yield of the battery cell.

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

[0005] Provide a battery cell housing, including:

[0006] A housing body, the housing body has a first side wall, and an explosion-proof through hole is provided on the first side wall;

[0007] An explosion-proof component, the explosion-proof component has a weak part, and the explosion-proof component is riveted to the first side wall so that the explosion-proof component blocks the explosion-proof through hole, and the position of the weak part on the explosion-proof component corresponds to the position of the explosion-proof through hole.

[0008] Optionally, a first riveting post is provided on the first side wall, a first riveting hole is provided on the explosion-proof component, and the first riveting post passes through the first riveting hole and is riveted to the explosion-proof component;

[0009] And / or, a second riveting hole is provided on the first side wall, a second riveting post is provided on the explosion-proof component, and the second riveting post passes through the second riveting hole and is riveted to the first side wall.

[0010] Optionally, the first riveting part of the first riveting post is welded to the explosion-proof component;

[0011] And / or, the second riveting part of the second riveting post is welded to the first side wall.

[0012] Optionally, two first riveting holes are formed in the explosion-proof component. The two first riveting holes are arranged at intervals along the length direction of the explosion-proof component. The weak part is located between the two first riveting holes. Two first riveting posts are arranged on the first side wall. The two first riveting posts are arranged in one-to-one correspondence with the two first riveting holes. The diameter D of the first riveting post satisfies D≥3.5mm.

[0013] Optionally, a limiting groove is formed on the first side wall. The explosion-proof component is located at the limiting groove. The first riveting post is located at the bottom of the limiting groove.

[0014] Optionally, the wall thickness H of the bottom of the limiting groove satisfies 0.5mm≤H≤0.8mm.

[0015] Optionally, the explosion-proof component includes a connecting piece and an explosion-proof valve. The connecting piece is riveted to the first side wall. A through hole is formed in the connecting piece. The explosion-proof valve is connected to the connecting piece and blocks the through hole. The through hole communicates with the explosion-proof through hole. The position of the weak part on the explosion-proof valve corresponds to the position of the through hole.

[0016] Optionally, the area of the projection of the explosion-proof valve on the plane where the first side wall is located is S1, and the area of the projection of the connecting piece on the plane where the first side wall is located is S2, satisfying: S1 / S2≤0.55.

[0017] Optionally, a sealing ring is further included. The sealing ring is clamped between the first side wall and the explosion-proof component, and the sealing ring does not interfere with the explosion-proof through hole.

[0018] Another object of the present invention is to provide an electric core, which can avoid the deformation of the electric core housing, prevent the scraping when the electrode group enters the housing, and improve the yield.

[0019] To achieve this object, the present invention adopts the following technical solutions:

[0020] An electric core is provided, including an electric core top cover, an electrode group, and the above-mentioned electric core housing. The electric core top cover is hermetically covered at the opening of the electric core housing to form the outer shell of the electric core. The electrode group is arranged inside the outer shell.

[0021] The beneficial effects of the present invention:

[0022] The present invention provides a battery cell housing, including a housing body and an explosion-proof component. Among them, the housing body has a first side wall, and an explosion-proof through hole is provided on the first side wall. The explosion-proof component has a weak part, and the explosion-proof component is riveted to the first side wall so that the explosion-proof component seals the explosion-proof through hole, and the position of the weak part on the explosion-proof component corresponds to the position of the explosion-proof through hole. By riveting the explosion-proof component on the housing body, it is no longer necessary to directly weld the explosion-proof valve on the housing body, thus fundamentally avoiding the deformation problem of the housing body caused by welding, ensuring that the electrode group can be normally inserted into the housing, and improving the yield of the battery cell.

[0023] The present invention also provides a battery cell, including a battery cell top cover, an electrode group, and the above-mentioned battery cell housing. The battery cell top cover is hermetically covered at the opening of the battery cell housing to form the outer shell of the battery cell, and the electrode group is arranged inside the outer shell. This battery cell can avoid the deformation of the battery cell housing, prevent the electrode group from being scratched when inserted into the housing, and improve the yield. Description of the Drawings

[0024] Figure 1 is a schematic structural diagram of the battery cell housing provided by the embodiment of the present invention from the first perspective;

[0025] Figure 2 is an exploded view of the battery cell housing provided by the embodiment of the present invention;

[0026] Figure 3 is a schematic structural diagram of the housing body provided by the embodiment of the present invention;

[0027] Figure 4 is a schematic structural diagram of the battery cell housing provided by the embodiment of the present invention from the second perspective;

[0028] Figure 5 is Figure 4 the A-A cross-sectional view in ;

[0029] Figure 6 is Figure 5 the enlarged view at B in ;

[0030] Figure 7 is a schematic structural diagram of the connecting piece provided by the embodiment of the present invention from the first perspective;

[0031] Figure 8 is a schematic structural diagram of the connecting piece provided by the embodiment of the present invention from the second perspective;

[0032] Figure 9 is Figure 8 the C-C cross-sectional view in.

[0033] In the figure:

[0034] 1. Housing body; 11. First side wall; 111. Limit groove; 1111. Explosion-proof through hole; 1112. First riveting post;

[0035] 2. Explosion-proof component; 21. Connector; 211. First riveting hole; 212. Through hole; 213. Counterbore; 214. Riveting groove; 215. Positioning groove; 22. Explosion-proof valve;

[0036] 3. Sealing ring. Detailed implementation manners

[0037] Before explaining any implementation manner of the present application in detail, it should be understood that the present application is not limited to the structural details and component arrangements set forth in the following description or shown in the above drawings.

[0038] In the present application, the terms "include", "comprise", "have" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device including a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "including one..." does not exclude the presence of additional identical elements in the process, method, article or device including such element.

[0039] In the present application, the term "and / or" describes the association relationship of associated objects and indicates that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in the present application generally represents an "and / or" relationship between the front and rear associated objects.

[0040] In the present application, the terms "connect", "combine", "couple", "mount" may be direct connection, combination, coupling or mounting, or may be indirect connection, combination, coupling or mounting. Among them, by way of example, direct connection means that two parts or components are connected together without setting an intermediate member, and indirect connection means that two parts or components are respectively connected to at least one intermediate member, and these two parts or components are connected through the intermediate member. In addition, "connect" and "couple" are not limited to physical or mechanical connection or coupling, and may include electrical connection or coupling.

[0041] In this application, those of ordinary skill in the art will understand that relative terms used in connection with quantities or conditions (e.g., "about", "approximately", "substantially", etc.) are intended to include the recited value and have the meaning indicated by the context. For example, such relative terms include at least the degree of error associated with the measurement of a particular value, tolerances resulting from manufacturing, assembly, use, etc. associated with a particular value. Such terms should also be considered to disclose a range defined by the absolute values of two endpoints. The relative terms may refer to plus or minus a certain percentage (e.g., 1%, 5%, 10% or more) of the indicated value. Numerical values that do not employ relative terms should also be disclosed as having tolerances. In addition, when expressing a relative angular positional relationship (e.g., substantially parallel, substantially perpendicular), "substantially" may refer to plus or minus a certain number of degrees (e.g., 1 degree, 5 degrees, 10 degrees or more) based on the indicated angle.

[0042] In this application, those of ordinary skill in the art will understand that the functions performed by a component may be performed by one component, multiple components, one part, or multiple parts. Similarly, the functions performed by a part may also be performed by one part, one component, or a combination of multiple parts.

[0043] In this application, the orientation terms such as "upper", "lower", "left", "right", "front", "rear", etc. are described based on the orientation and positional relationship shown in the drawings, and should not be construed as a limitation on the embodiments of this application. In addition, in the context, it should also be understood that when it is mentioned that one element is connected "above" or "below" another element, it can not only be directly connected "above" or "below" another element, but also be indirectly connected "above" or "below" another element through an intermediate element. It should also be understood that orientation terms such as the upper side, lower side, left side, right side, front side, rear side, etc. not only represent the positive orientation, but can also be understood as the side orientation. For example, the lower side may include directly below, lower left, lower right, lower front, and lower rear, etc.

[0044] To ensure the safety of the use of the battery cell, an explosion-proof valve is generally provided in the battery cell. Once the battery cell undergoes thermal runaway, the explosion-proof valve can release the high-temperature gas inside the battery cell at a fixed point to prevent the battery cell from exploding. In the prior art, the explosion-proof valve is generally provided on the top cover of the battery cell. However, the top cover of the battery cell is located at one end of the length direction of the battery cell, and the path for the gas to reach the explosion-proof valve is relatively long, which is not conducive to improving the safety of the battery cell. Setting the explosion-proof valve on the side wall of the battery cell with a smaller area can shorten the exhaust path and improve the safety performance. However, the wall thickness of the battery cell housing is smaller than that of the top cover of the battery cell, and in order to arrange the explosion-proof valve, an opening needs to be made on the battery cell housing, and the structural strength here will be very weak. Welding the explosion-proof valve easily causes deformation at the adjacent position of the battery cell housing. The deformation is generally an inward concave deformation, which will affect the insertion of the electrode assembly into the housing, cause the electrode assembly to rub, and affect the yield of the battery cell.

[0045] To solve the above problems, this embodiment provides an electric core housing that can avoid deformation, prevent scratching when the electrode group is inserted into the housing, and improve the yield of the electric core.

[0046] As Figures 1 - 8 shown, the electric core housing of this embodiment includes a housing body 1 and an explosion-proof component 2. Among them, the housing body 1 has a first side wall 11, and an explosion-proof through hole 1111 is provided on the first side wall 11. The explosion-proof component 2 has a weak part. The explosion-proof component 2 is riveted to the first side wall 11 so that the explosion-proof component 2 plugs the explosion-proof through hole 1111, and the position of the weak part on the explosion-proof component 2 corresponds to the position of the explosion-proof through hole 1111. By riveting the explosion-proof component 2 on the housing body 1, it is no longer necessary to directly weld the explosion-proof valve 22 on the housing body 1, which can fundamentally avoid the deformation problem of the housing body 1 caused by welding, ensure the normal insertion of the electrode group into the housing, and improve the yield of the electric core.

[0047] To realize the welded connection between the explosion-proof component 2 and the first side wall 11, optionally, in this embodiment, the first side wall 11 has a first riveting post 1112, and a first riveting hole 211 is provided on the explosion-proof component 2. The first riveting post 1112 passes through the first riveting hole 211 and is riveted to the explosion-proof component 2. The explosion-proof component 2 is located outside the first side wall 11, and the setting method of this embodiment facilitates the riveting operation.

[0048] Optionally, in this embodiment, to further strengthen the connection strength between the explosion-proof component 2 and the first side wall 11, the first riveting part of the first riveting post 1112 is welded to the explosion-proof component 2. That is, the end of the first riveting post 1112 passes through the first riveting hole 211 and is deformed by riveting to form a first riveting part. The first riveting part protrudes radially along the undeformed part of the first riveting post 1112 to limit the explosion-proof component 2 from detaching from the first side wall 11. The first riveting part is further welded to the outer end face of the explosion-proof component 2 to make the connection between the explosion-proof component 2 and the first side wall 11 more firm. It can be known that since the welding area between the first riveting part and the explosion-proof component 2 is small, the influence of the welding on the overall first side wall 11 through the first riveting part is very small, and neither the first side wall 11 nor the adjacent side walls will have concave deformation. The explosion-proof component 2 may be deformed by welding, but since the explosion-proof component 2 is located outside the first side wall 11, it will not affect the insertion of the electrode group into the housing. As long as the seal between the explosion-proof component 2 and the first side wall 11 is well done.

[0049] Optionally, a riveting groove 214 is provided on the outer end face of the explosion-proof component 2. The riveting groove 214 is arranged around the first riveting hole 211, and the first riveting part is located in the riveting groove 214 to facilitate the riveting forming of the first riveting part. Optionally, the outer end face of the first riveting part is flush with the outer end face of the explosion-proof component 2.

[0050] Optionally, in other embodiments, a second riveting hole may also be formed on the first side wall 11, and a second riveting post is provided on the explosion-proof component 2. The second riveting post passes through the second riveting hole and is riveted to the first side wall 11. Optionally, the connection strength between the explosion-proof component 2 and the first side wall 11 may be further enhanced by welding the second riveting portion of the second riveting post to the first side wall 11.

[0051] Optionally, in this embodiment, in order to ensure the balanced force of the explosion-proof component 2, two first riveting holes 211 are formed on the explosion-proof component 2. The two first riveting holes 211 are arranged at intervals along the length direction of the explosion-proof component 2. The weak part is located between the two first riveting holes 211. Two first riveting posts 1112 are provided on the first side wall 11, and the two first riveting posts 1112 are arranged in one-to-one correspondence with the two first riveting holes 211. Optionally, the sizes of the two first riveting posts 1112 are the same, further ensuring that the two ends of the explosion-proof component 2 along the length direction receive balanced riveting pressure.

[0052] Optionally, the diameter D of the first riveting post 1112 satisfies D≥3.5 mm. If the diameter D of the first riveting post 1112 is less than 3.5 mm, the connection strength of the explosion-proof component 2 at the first side wall 11 cannot be guaranteed, the tensile and torsional resistance performance of the explosion-proof component 2 does not meet the quality requirements, and there is a possibility of leakage of the battery cell, and the quality cannot be guaranteed.

[0053] In order to facilitate positioning during the assembly of the explosion-proof component 2, optionally, a limiting groove 111 is formed on the first side wall 11. The explosion-proof component 2 is located at the limiting groove 111, and the first riveting post 1112 is located at the bottom of the limiting groove 111. It can be known that the limiting groove 111 is located on the outer wall surface of the first side wall 11, and the explosion-proof through hole 1111 is also formed at the bottom of the limiting groove 111. The two first riveting posts 1112 are respectively located at both ends of the explosion-proof through hole 1111.

[0054] As Figure 6 shown, optionally, the wall thickness H of the bottom of the limiting groove 111 satisfies 0.5 mm≤H≤0.8 mm. The bottom of the limiting groove 111 is the position where the explosion-proof component 2 is supported. If the wall thickness H at this position is less than 0.5 mm, the structural strength here is insufficient, the supporting ability of the limiting groove 111 for the explosion-proof component 2 is insufficient, the tensile and torsional resistance performance of the explosion-proof component 2 cannot meet the quality requirements, there is a possibility of leakage of the battery cell, and the quality of the battery cell cannot be guaranteed.

[0055] Optionally, in this embodiment, the explosion-proof assembly 2 includes a connector 21 and an explosion-proof valve 22, the connector 21 is riveted to the first side wall 11, a through hole 212 is provided on the connector 21, the explosion-proof valve 22 is connected to the connector 21, and the through hole 212 is blocked, the through hole 212 is connected to the explosion-proof through hole 1111, and the position of the weak part on the explosion-proof valve 22 corresponds to the position of the through hole 212. Optionally, the explosion-proof valve 22 is welded on the connector 21 to ensure the connection strength between the two. Optionally, the explosion-proof valve 22 is first welded on the connector 21, and then the connector 21 is riveted and welded at the first side wall 11. The advantage of this arrangement is that poor welding of the explosion-proof valve 22 will not directly scrap a shell body 1, which can achieve cost reduction. In addition, the welding of the welding connector 21 and the explosion-proof valve 22 belongs to the welding between monomers, which is smaller in size and simpler in planar structure, more conducive to automated production, convenient for welding operation, and also convenient for subsequent air tightness detection, thereby improving production efficiency.

[0056] Optionally, a sink groove 213 is formed on the connecting member 21, the through hole 212 is located at the bottom of the sink groove 213, and the explosion-proof valve 22 is located in the sink groove 213, so that the bottom of the sink groove 213 supports the explosion-proof valve 22. Optionally, the outward end surface of the explosion-proof valve 22 is flush with the outward end surface of the connecting member 21, that is, the depth of the sink groove 213 is equivalent to the thickness of the explosion-proof valve 22.

[0057] Of course, in other embodiments, the connecting piece 21 and the explosion-proof valve 22 may also be integrally formed to improve the structural strength of the connection between the two, thereby eliminating the welding step of the connecting piece 21 and the explosion-proof valve 22 .

[0058] like Figure 4 As shown, optionally, the area of ​​the projection of the explosion-proof valve 22 toward the plane where the first side wall 11 is located is S1, and the area of ​​the projection of the connecting member 21 toward the plane where the first side wall 11 is located is S2, satisfying: S1 / S2≤0.55. If the ratio of the area S1 of the projection of the explosion-proof valve 22 toward the plane where the first side wall 11 is located to the area S2 of the projection of the connecting member 21 toward the plane where the first side wall 11 is located is greater than 0.55, that is, the proportion of the explosion-proof valve 22 on the connecting member 21 is too large, the structural strength of the connecting member 21 itself is insufficient, and the welding with the explosion-proof valve 22 and the riveting welding with the first side wall 11 may affect the flatness of the connecting member 21, causing air leakage and the like.

[0059] In order to ensure the airtightness between the connector 21 and the first side wall 11, the battery cell housing may further include a sealing ring 3, which is sandwiched between the first side wall 11 and the explosion-proof component 2, and the sealing ring 3 does not interfere with the explosion-proof through hole 1111 or the through hole 212. Figure 2 As shown, in this embodiment, the sealing ring 3 is sleeved on the outer sides of the two first riveted columns 1112. Optionally, the sealing ring 3 may be made of fluororubber, or other high temperature resistant materials.

[0060] Optionally, as Figure 7 and Figure 8 shown, a positioning groove 215 is provided in a ring shape on the end surface of the connecting member 21 facing the inside of the battery cell. The sealing ring 3 is located in the positioning groove 215, which can facilitate the assembly of the sealing ring 3 and prevent the sealing ring 3 from shifting, ensuring the circumferential sealing connection between the connecting member 21 and the bottom of the limiting groove 111 of the first side wall 11.

[0061] Optionally, the housing body 1 is formed by processes such as extrusion and high-frequency welding. Optionally, in this embodiment, the materials of the housing body 1 and the connecting member 21 are both aluminum.

[0062] Optionally, the first side wall 11 is a side wall on one side of the housing body 1 along its width direction. If the explosion-proof valve 22 is directly welded to the first side wall 11, then the two side walls with the largest areas adjacent to the first side wall 11 are prone to concave deformation.

[0063] In order to verify the effect of the battery cell housing in solving the problem of welding deformation of the housing body 1, this embodiment provides a set of test data as shown in Table 1 and Table 2 below. Table 1 lists the dimensions of the battery cell housings of six groups of examples, and Table 2 lists the dimensions of the battery cell housings of five groups of comparative examples. The similarities between the battery cell housings of the six groups of examples and the five groups of comparative examples include: the material of the explosion-proof valve 22 is MXF2, and the area S2 of the projection of the connecting member 21 on the plane where the first side wall 11 is located is 994.8 mm 2 .

[0064] The key dimensional parameters of the cell housings of the six groups of examples in Table 1 all meet the above-mentioned more optimal value ranges. For example, the wall thickness H at the bottom of the limiting groove 111 is 0.5 mm, which meets the value range of 0.5 mm - 0.8 mm. The diameter D of the first riveting post 1112 is greater than or equal to 3.5 mm. The ratio of the area S1 of the projection of the explosion-proof valve 22 onto the plane where the first side wall 11 is located to the area S2 of the projection of the connecting member 21 onto the plane where the first side wall 11 is located is also less than or equal to 0.55. The processing process of the cell housing includes first welding the explosion-proof valve 22 onto the connecting member 21, and then riveting and welding the explosion-proof assembly 2 as a whole onto the first side wall 11. After inspection, no depression deformation occurs on the side wall with the largest area of the cell housings of these six groups of examples, and no deformation occurs on the first side wall 11 either. The anti-pushing ability and anti-twisting ability of the connecting member 21 both meet the quality requirements, and the airtightness between the explosion-proof valve 22 and the connecting member 21 is good, and the airtightness between the connecting member 21 and the first side wall 11 is also good. The bursting pressure of the explosion-proof valve 22 also meets the preset pressure range. It can be seen that the cell housing can completely solve the problem of welding deformation of the housing body 1, ensure the smooth insertion of the electrode group into the housing, and the electrode group will not be scratched. Moreover, the cell housing that meets the above-mentioned more optimal value ranges can meet the quality requirements in terms of airtightness, anti-pushing and anti-twisting abilities, etc., and the overall yield of the cell is greatly improved.

[0065] Table 1

[0066]

[0067]

[0068] The diameter D of the first riveting post 1112 of the cell housing of Comparative Example 1 in Table 2 is 3 mm, which is less than the minimum value of the more optimal range of 3.5 mm. After inspection, no depression deformation occurs on the side wall with the largest area of this group of cell housings, and no deformation occurs on the first side wall 11 either. The electrode group can be smoothly inserted into the housing. Also, the airtightness between the explosion-proof valve 22 and the connecting member 21 of this group of cell housings is good, the airtightness between the connecting member 21 and the first side wall 11 is also good, and the bursting pressure of the explosion-proof valve 22 also meets the preset pressure range. However, the anti-pushing ability and anti-twisting ability of the connecting member 21 of this group of cell housings are both lower than 800 N, which does not meet the quality requirements and there is a risk of cell leakage and failure.

[0069] The ratio of the area S1 of the projection of the explosion-proof valve 22 of the battery cell housing in Comparative Example 2 in Table 2 onto the plane where the first side wall 11 is located to the area S2 of the projection of the connecting member 21 onto the plane where the first side wall 11 is located is greater than 0.55, exceeding the more optimal value range. After inspection, no depression deformation occurred on the side walls with the largest area of this group of battery cell housings, and no deformation occurred on the first side wall 11 either. The electrode group can be smoothly inserted into the housing, and the thrust resistance and torsion resistance of the connecting member 21 of this group of battery cell housings both meet the quality requirements. However, the flatness of the connecting member 21 of this group of battery cell housings has out-of-tolerance deformation, that is, deformation with a deformation depth greater than or equal to 0.3 mm. Therefore, the airtightness detection of this group of battery cell housings shows poor results, and the qualification rate is less than 98%. This is because the proportion of the explosion-proof valve 22 on the connecting member 21 is too large, and the structural strength of the connecting member 21 itself is insufficient. The welding of the connecting member 21 with the explosion-proof valve 22 and the riveting welding with the first side wall 11 may both affect the flatness of the connecting member 21, resulting in problems with poor airtightness.

[0070] The ratio of the area S1 of the projection of the explosion-proof valve 22 of the battery cell housing in Comparative Example 3 in Table 2 onto the plane where the first side wall 11 is located to the area S2 of the projection of the connecting member 21 onto the plane where the first side wall 11 is located further increases. After inspection, no depression deformation occurred on the side walls with the largest area of this group of battery cell housings, and no deformation occurred on the first side wall 11 either. The electrode group can be smoothly inserted into the housing, and the thrust resistance and torsion resistance of the connecting member 21 of this group of battery cell housings both meet the quality requirements. However, the flatness of the connecting member 21 of this group of battery cell housings also has out-of-tolerance deformation, that is, deformation with a deformation depth greater than or equal to 0.3 mm. The airtightness detection of this group of battery cell housings shows poor results, and the qualification rate is less than 97%, that is, the qualification rate is further reduced compared with Comparative Example 2. It can be seen that as the proportion of the explosion-proof valve 22 on the connecting member 21 further increases, the structural strength of the connecting member 21 itself further decreases, and the influence of the welding of the connecting member 21 with the explosion-proof valve 22 and the riveting welding with the first side wall 11 on the flatness of the connecting member 21 further increases, and the probability of problems with poor airtightness increases somewhat.

[0071] For Comparative Example 4 in Table 2, the ratio of the area S1 of the projection of the explosion-proof valve 22 of the battery cell housing towards the plane where the first side wall 11 is located to the area S2 of the projection of the connecting member 21 towards the plane where the first side wall 11 is located is 0.7, which is further increased compared to Comparative Example 3. After testing, no depression deformation occurred on the side walls with the largest area of this group of battery cell housings, and the first side wall 11 did not deform either. The electrode group could be smoothly inserted into the housing, and the thrust resistance and torsion resistance of the connecting member 21 of this group of battery cell housings both met the quality requirements. However, the flatness of the connecting member 21 of this group of battery cell housings was also out of tolerance, that is, the deformation depth was greater than or equal to 0.3 mm. The airtightness test of this group of battery cell housings showed defects, and the qualified rate was less than 95%, that is, the qualified rate was further reduced compared to Comparative Example 3. As the proportion of the explosion-proof valve 22 on the connecting member 21 further increases, the structural strength of the connecting member 21 itself further decreases, and the influence of the welding between the connecting member 21 and the explosion-proof valve 22 and the riveting welding with the first side wall 11 on the flatness of the connecting member 21 further increases, and the probability of the occurrence of airtightness defects also increases.

[0072] For Comparative Example 5 in Table 2, the wall thickness H at the bottom of the limiting groove 111 of the battery cell housing is less than 0.5 mm. After testing, no depression deformation occurred on the side walls with the largest area of this group of battery cell housings, and the first side wall 11 did not deform either. The electrode group could be smoothly inserted into the housing. Moreover, the airtightness between the explosion-proof valve 22 and the connecting member 21 of this group of battery cell housings was good, and the airtightness between the connecting member 21 and the first side wall 11 was also good. The bursting pressure of the explosion-proof valve 22 also met the preset pressure range. However, the thrust resistance and torsion resistance of the connecting member 21 of this group of battery cell housings were both lower than 800 N, which did not meet the quality requirements, and there was a risk of battery cell leakage failure. This is because if the wall thickness H at the bottom of the limiting groove 111 is less than 0.5 mm, the structural strength here is insufficient, the supporting ability of the limiting groove 111 for the explosion-proof component 2 is insufficient, and the tensile and torsional resistance performance of the explosion-proof component 2 will be affected.

[0073] It can be seen that even for a battery cell housing with dimensional parameters not meeting the optimal value range, the problem of welding deformation of the housing body 1 can be completely avoided, ensuring that the electrode group can be smoothly inserted into the housing without being scratched. A battery cell housing with dimensional parameters meeting the optimal value range can avoid the problems of insufficient tensile and torsional resistance of the explosion-proof component 2 and poor airtightness, ensuring the stability of the battery cell quality.

[0074] Table 2

[0075] Category Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 H (mm) 0.5 0.5 0.5 0.5 0.45 D (mm) 3.00 3.50 3.50 4.00 4.00 <![CDATA[S1(mm 2 )]]> 149.22 576.98 646.62 696.36 397.92 <![CDATA[S2(mm 2 )]]> 994.80 994.80 994.80 994.80 994.80 S1 / S2 0.15 0.58 0.65 0.70 0.40

[0076] An explosion-proof valve 22 is provided on the battery cell housing. When the battery cell undergoes thermal runaway, the path for valve opening and gas exhaust is shorter, and the safety performance is higher. Moreover, the connecting member 21 and the first side wall 11 are fixedly connected by riveting and welding, and sealed by a sealing ring 3. One welding area of the battery cell housing is the riveting joint. Since its range is small, it will not affect the housing body 1. And because the connecting member 21 and the explosion-proof valve 22 belong to the welding between monomers, the size is smaller and the planar structure is simpler, which is more conducive to welding operations and subsequent airtightness detection. Another welding area of the battery cell housing is between the explosion-proof valve 22 and the connecting member 21, which will not affect the housing body 1 either. That is, even if the explosion-proof valve 22 is poorly welded, the housing body 1 will not be directly scrapped, which can reduce costs and increase the anti-deformation ability at the explosion-proof valve 22. The battery cell housing can completely solve the problem of the electrode group being scratched when entering the housing, and improve the product yield. And through a more optimized size design, including that the wall thickness H at the bottom of the limiting groove 111 conforms to the value range of 0.5 mm - 0.8 mm, the diameter D of the first riveting post 1112 is greater than or equal to 3.5 mm, and the ratio of the area S1 of the projection of the explosion-proof valve 22 onto the plane where the first side wall 11 is located to the area S2 of the projection of the connecting member 21 onto the plane where the first side wall 11 is located is less than or equal to 0.55, it can ensure that the tensile and torsional resistance of the explosion-proof component 2 of the battery cell housing meets the quality requirements, the airtightness between the explosion-proof valve 22 and the connecting member 21 is good, the airtightness between the connecting member 21 and the first side wall 11 is also good, and the bursting pressure of the explosion-proof valve 22 also conforms to the preset pressure range, thus ensuring the stability of the battery cell quality and improving its overall yield.

[0077] This embodiment also provides a battery cell, including a battery cell top cover, an electrode group, and the above-mentioned battery cell housing. The battery cell top cover is hermetically covered at the opening of the battery cell housing to form the outer shell of the battery cell, and the electrode group is arranged inside the outer shell. This battery cell can avoid deformation of the battery cell housing, prevent the electrode group from being scratched when entering the housing, and improve the yield.

[0078] Obviously, the above-mentioned embodiments of the present invention are only examples for clearly explaining the present invention, and are not intended to limit the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims

1. Battery cell housing, characterized in that, Comprising: A housing body (1), the housing body (1) having a first side wall (11), and an explosion-proof through hole (1111) being formed in the first side wall (11); An explosion-proof component (2), the explosion-proof component (2) having a weak part, the explosion-proof component (2) being riveted to the first side wall (11) so that the explosion-proof component (2) blocks the explosion-proof through hole (1111), and the position of the weak part on the explosion-proof component (2) corresponding to the position of the explosion-proof through hole (1111).

2. The cell housing according to claim 1, wherein The first side wall (11) has a first riveting post (1112), a first riveting hole (211) being formed in the explosion-proof component (2), and the first riveting post (1112) passing through the first riveting hole (211) and being riveted to the explosion-proof component (2); And / or, a second riveting hole is formed in the first side wall (11), a second riveting post is provided on the explosion-proof component (2), and the second riveting post passes through the second riveting hole and is riveted to the first side wall (11).

3. The cell housing according to claim 2, characterized in that, A first riveting portion of the first riveting post (1112) is welded to the explosion-proof component (2); And / or, a second riveting portion of the second riveting post is welded to the first side wall (11).

4. The cell housing according to claim 3, characterized in that, Two of the first riveting holes (211) are formed in the explosion-proof component (2), the two first riveting holes (211) being spaced apart along the length direction of the explosion-proof component (2), the weak part being located between the two first riveting holes (211), two of the first riveting posts (1112) being provided on the first side wall (11), the two first riveting posts (1112) being arranged in one-to-one correspondence with the two first riveting holes (211), and the diameter D of the first riveting post (1112) satisfying D≥3.5 mm.

5. The cell housing according to any one of claims 2-4, characterized in that, A limiting groove (111) is formed in the first side wall (11), the explosion-proof component (2) being located at the limiting groove (111), and the first riveting post (1112) being located at the bottom of the limiting groove (111).

6. The cell housing according to claim 5, characterized in that, The wall thickness H of the bottom of the limiting groove (111) satisfies 0.5 mm≤H≤0.8 mm.

7. The cell housing according to any one of claims 1-4, characterized in that, The explosion-proof component (2) includes a connecting member (21) and an explosion-proof valve (22), the connecting member (21) being riveted to the first side wall (11), a through hole (212) being formed in the connecting member (21), the explosion-proof valve (22) being connected to the connecting member (21) and blocking the through hole (212), the through hole (212) communicating with the explosion-proof through hole (1111), and the position of the weak part on the explosion-proof valve (22) corresponding to the position of the through hole (212).

8. The cell housing according to claim 7, characterized in that, The area of the projection of the explosion-proof valve (22) onto the plane where the first side wall (11) is located is S1, and the area of the projection of the connecting member (21) onto the plane where the first side wall (11) is located is S2, satisfying: S1 / S2≤0.

55.

9. The cell housing according to any one of claims 1-4, characterized in that, It further includes a sealing ring (3), the sealing ring (3) is clamped between the first side wall (11) and the explosion-proof component (2), and the sealing ring (3) does not interfere with the explosion-proof through hole (1111).

10. The battery cell is characterized in that, It includes a battery cell top cover, a pole group and the battery cell housing according to any one of claims 1-9, the battery cell top cover is hermetically covered at the opening of the battery cell housing to form the outer shell of the battery cell, and the pole group is arranged inside the outer shell.

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