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 anti-explosion valve. Wherein the shell body comprises a first side wall, a second side wall and a third side wall, the second side wall and the third side wall are oppositely arranged in the thickness direction of the shell body, the second side wall is provided with a first boss which is formed by stamping and protrudes outwards, and the third side wall is provided with a second boss which is formed by stamping and protrudes outwards. The anti-explosion valve is welded to the first side wall, and the first boss and the second boss are both arranged close to the anti-explosion valve, so that deformation caused by welding of the anti-explosion valve is at least partially located at the first boss and the second boss. The battery cell comprises a pole group, a battery cell top cover and the battery cell shell, the battery cell top cover hermetically covers the opening of the battery cell shell to form a shell, and the pole group is positioned in the shell. According to the battery cell, the rubbing degree of the pole group when the pole group enters the shell can be reduced, so that the yield of the battery cell 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] By providing an explosion-proof valve, the battery cell can release the internal high-temperature gas at a fixed point during thermal runaway, preventing the battery cell from exploding and ensuring the safety of the battery cell. 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 place is weak, and welding is likely to cause deformation of the battery cell housing. The deformation generally occurs on the two side walls with the largest area adjacent to the side wall where the explosion-proof valve is welded. Concavities will appear on these two side walls, and the concave deformation will affect the insertion of the electrode assembly into the housing, causing the electrode assembly to rub against the housing and affecting 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 help reduce the degree of rubbing when the electrode assembly is inserted into the housing and improve the yield of the battery cell.

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

[0005] Provide a battery cell housing, comprising:

[0006] A housing body, the housing body includes a first side wall, a second side wall and a third side wall that are oppositely arranged along its own thickness direction, the second side wall has a first boss formed by stamping and protruding outward, and the third side wall has a second boss formed by stamping and protruding outward;

[0007] An explosion-proof valve, the explosion-proof valve is welded on the first side wall, and both the first boss and the second boss are arranged close to the explosion-proof valve, so that the deformation caused by welding the explosion-proof valve is at least partially located at the first boss and the second boss.

[0008] Optionally, one side edge of the first boss coincides with the side edge between the second side wall and the first side wall;

[0009] And / or, one side edge of the second boss coincides with the side edge between the third side wall and the first side wall.

[0010] Optionally, the explosion-proof valve is located in the middle of the first side wall in the first direction, where the first direction is the length direction of the housing body, the first boss is located in the middle of the second side wall in the first direction, and / or the second boss is located in the middle of the third side wall in the first direction.

[0011] Optionally, the area of the projection of the explosion-proof valve onto a plane perpendicular to the width direction of the housing body is S1, and the area of the first protruding end face of the first boss is S21, satisfying: S21 / S1 ≥ 0.8, and / or S21 / S1 < 1.3;

[0012] and / or, the area of the projection of the explosion-proof valve onto a plane perpendicular to the width direction of the housing body is S1, and the area of the second protruding end face of the second boss is S22, satisfying: S22 / S1 ≥ 0.8, and / or S22 / S1 < 1.3.

[0013] Optionally, along the length direction of the housing body, the length of the explosion-proof valve is L, and the length of the first boss is W1, satisfying: L > W1;

[0014] and / or, along the length direction of the housing body, the length of the explosion-proof valve is L, and the length of the second boss is W2, satisfying: L > W2.

[0015] Optionally, the protruding height H1 of the first boss relative to the second side wall satisfies H1 ≥ 0.25 mm, and / or H1 ≤ 0.4 mm;

[0016] The protruding height H2 of the second boss relative to the third side wall satisfies H2 ≥ 0.25 mm, and / or H2 ≤ 0.4 mm.

[0017] Optionally, the wall thickness T1 of the first boss satisfies T1 ≥ 0.5 mm;

[0018] and / or, the wall thickness T2 of the second boss satisfies T2 ≥ 0.5 mm.

[0019] Optionally, along the thickness direction of the housing body, the explosion-proof valve is located in the middle of the first side wall, and the first boss and the second boss are symmetrically arranged.

[0020] Optionally, an explosion-proof groove is provided on the outer side of the first side wall, an explosion-proof through hole is provided at the bottom of the explosion-proof groove, the explosion-proof valve is located in the explosion-proof groove, and the notch of the explosion-proof valve is within the range of the explosion-proof through hole.

[0021] Another object of the present invention is to provide an electric core, which can help reduce the degree of being scratched when the electrode group is inserted into the housing and improve the yield of the electric core.

[0022] To achieve this purpose, the present invention adopts the following technical solutions:

[0023] Provide an electric core, including a pole group, an electric core top cover, 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 a housing, and the pole group is located inside the housing.

[0024] Beneficial effects of the present invention:

[0025] The present invention provides an electric core housing, including a housing body and an explosion-proof valve. Among them, the housing body includes a first side wall, a second side wall and a third side wall that are oppositely arranged along its own thickness direction. The second side wall has a first boss formed by stamping and protruding outward, and the third side wall has a second boss formed by stamping and protruding outward. The explosion-proof valve is welded to the first side wall, and both the first boss and the second boss are arranged close to the explosion-proof valve, so that the deformation caused by the welding of the explosion-proof valve is at least partially located at the first boss and the second boss. Since the adjacent second side wall and third side wall are prone to concave deformation when the explosion-proof valve is welded to the first side wall, the setting of the first boss and the second boss can, on the one hand, improve the structural strength and reduce the degree of deformation, and on the other hand, increase the distance between the convex back surface of the concave deformation located on the first boss and the second boss and the pole group, thereby reducing the degree of scraping of the pole group when entering the housing, and thus improving the yield of the electric core.

[0026] The present invention also provides an electric core, including a pole group, an electric core top cover, 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 a housing, and the pole group is located inside the housing. This electric core can help reduce the degree of scraping of the pole group when entering the housing, thereby improving the yield of the electric core. Description of the drawings

[0027] Figure 1 is a schematic structural diagram of the first perspective of the electric core housing provided by the embodiment of the present invention;

[0028] Figure 2 is a schematic structural diagram of the second perspective of the electric core housing provided by the embodiment of the present invention;

[0029] Figure 3 is Figure 2 the A-A cross-sectional view in

[0030] Figure 4 is Figure 3 the enlarged view of B in

[0031] Figure 5 is a schematic structural diagram of the third perspective of the electric core housing provided by the embodiment of the present invention.

[0032] In the figure:

[0033] 1. Housing body; 11. First side wall; 111. Explosion-proof through hole; 12. Second side wall; 121. First boss; 1211. First protruding end face; 13. Third side wall; 131. Second boss; 1311. Second protruding end face;

[0034] 2. Explosion-proof valve. Detailed implementation manners

[0035] 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.

[0036] In the present application, the terms "comprise", "include", "have" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising 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 "comprising a..." does not exclude the presence of additional identical elements in the process, method, article or device comprising such element.

[0037] 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, in the present application, the character " / " generally indicates that the associated objects before and after are in an "and / or" relationship.

[0038] 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.

[0039] In this application, those of ordinary skill in the art will understand that relative terms used in connection with quantities or conditions (such as "about", "approximately", "substantially", etc.) are intended to include the stated 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. Relative terms may refer to a plus or minus a certain percentage (such as 1%, 5%, 10% or more) of the indicated value. Numerical values without the use of relative terms should also be disclosed as specific values with tolerances. In addition, when expressing relative angular positional relationships (such as substantially parallel, substantially perpendicular), "substantially" may refer to a plus or minus a certain number of degrees (such as 1 degree, 5 degrees, 10 degrees or more) based on the indicated angle.

[0040] In this application, those of ordinary skill in the art will understand that the functions performed by a component can be performed by one component, multiple components, one part, or multiple parts. Similarly, the functions performed by a part can also be performed by one part, one component, or a combination of multiple parts.

[0041] 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 can include directly below, lower left, lower right, lower front, and lower rear, etc.

[0042] By providing an explosion-proof valve, the battery cell can release the internal high-temperature gas at a fixed point in case of thermal runaway, preventing the battery cell from exploding and ensuring the safety of the battery cell. 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 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 place is weak, and welding is likely to cause deformation of the battery cell housing. Deformation generally occurs on the two side walls with the largest area adjacent to the side wall where the explosion-proof valve is welded, and these two side walls will have inward concavities. The inward concavity deformation will affect the insertion of the electrode assembly into the housing, causing the electrode assembly to rub, and affecting the yield of the battery cell.

[0043] To solve the above problems, this embodiment provides a battery cell housing, which can help reduce the degree of scratching when the electrode group is inserted into the housing and improve the yield of the battery cell.

[0044] As Figures 1 - 5 shown, the battery cell housing of this embodiment includes a housing body 1 and an explosion-proof valve 2. Among them, the housing body 1 includes a first side wall 11, and a second side wall 12 and a third side wall 13 that are oppositely arranged along its own thickness direction. The second side wall 12 has a first boss 121 formed by stamping and protruding outward, and the third side wall 13 has a second boss 131 formed by stamping and protruding outward. The explosion-proof valve 2 is welded to the first side wall 11, and both the first boss 121 and the second boss 131 are arranged close to the explosion-proof valve 2, so that the deformation caused by the welding of the explosion-proof valve 2 is at least partially located at the first boss 121 and the second boss 131.

[0045] When the explosion-proof valve 2 is welded to the first side wall 11, the adjacent second side wall 12 and third side wall 13 are prone to concave deformation. Therefore, the setting of the first boss 121 and the second boss 131 can, on the one hand, improve the structural strength and reduce the degree of deformation, and on the other hand, increase the distance between the convex back of the concave deformation on the first boss 121 and the second boss 131 and the electrode group, that is, the degree of scratching when the electrode group is inserted into the housing can be reduced, thereby improving the yield of the battery cell.

[0046] Optionally, the housing body 1 is formed by extrusion molding, which can ensure the structural strength and improve the manufacturing efficiency.

[0047] Since the position of the second side wall 12 closer to the first side wall 11 is more prone to concave deformation, on the basis of a certain area of the first boss 121, in order to maximize the area of the first boss 121 covering the concave deformation, optionally, one side of the first boss 121 coincides with the side between the second side wall 12 and the first side wall 11.

[0048] Similarly, since the position of the third side wall 13 closer to the first side wall 11 is more prone to concave deformation, on the basis of a certain area of the second boss 131, in order to maximize the area of the second boss 131 covering the concave deformation, optionally, one side of the second boss 131 coincides with the side between the third side wall 13 and the first side wall 11.

[0049] Optionally, along the length direction of the housing body 1, the midline of the first boss 121 intersects with the midline of the explosion-proof valve 2. That is, when the explosion-proof valve 2 is located in the middle of the first side wall 11 along its own length direction, the first boss 121 is also located in the middle of the second side wall 12 along its own length direction. When the explosion-proof valve 2 is close to one end of the first side wall 11 along its own length direction, the first boss 121 is also close to the same end of the second side wall 12 along its own length direction. That is, along the length direction of the housing body 1, the position of the first boss 121 is adjusted with the position of the explosion-proof valve 2 to ensure that when the area of the first boss 121 is constant, the concave deformation area on the second side wall 12 is covered to the greatest extent.

[0050] Optionally, along the length direction of the housing body 1, the midline of the second boss 131 intersects with the midline of the explosion-proof valve 2. That is, when the explosion-proof valve 2 is located in the middle of the first side wall 11 along its own length direction, the second boss 131 is also located in the middle of the third side wall 13 along its own length direction. When the explosion-proof valve 2 is close to one end of the first side wall 11 along its own length direction, the second boss 131 is also close to the same end of the third side wall 13 along its own length direction. That is, along the length direction of the housing body 1, the position of the second boss 131 is adjusted with the position of the explosion-proof valve 2 to ensure that when the area of the second boss 131 is constant, the concave deformation area on the third side wall 13 is covered to the greatest extent.

[0051] Optionally, in this embodiment, the explosion-proof valve 2 is located in the middle of the first side wall 11 along the first direction, the first direction is the length direction of the housing body 1, the first boss 121 is located in the middle of the second side wall 12 along the first direction, and optionally, the second boss 131 is located in the middle of the third side wall 13 along the first direction.

[0052] Optionally, the area of the projection of the explosion-proof valve 2 onto the plane perpendicular to the width direction of the housing body 1 is S1, and the area of the first protruding end face 1211 of the first boss 121 is S21, satisfying: S21 / S1 ≥ 0.8, and optionally, S21 / S1 < 1.3. As Figure 2 shown, taking the explosion-proof valve 2 as an elliptical structure as an example, S1 is the area of the ellipse drawn by the outermost circle of the elliptical structure. When the ratio of S21 to S1 is less than 0.8, if the size of the explosion-proof valve 2 remains unchanged, the area of the first protruding end face 1211 of the first boss 121 will be too small, and the effect of relieving deformation will be poor. Concave deformation will still occur in the area outside the first boss 121 on the second side wall 12. When the ratio of S21 to S1 is greater than or equal to 1.3, if the size of the explosion-proof valve 2 remains unchanged, the area of the first protruding end face 1211 of the first boss 121 will be too large, occupying the space of the battery cell grouping, which is not conducive to the spatial layout of the battery module. Moreover, the flatness of the large surface is difficult to control, the process difficulty increases, and the flatness of the first protruding end face 1211 of the first boss 121 is likely to be unqualified.

[0053] Optionally, the area of the projection of the explosion-proof valve 2 onto a plane perpendicular to the width direction of the housing body 1 is S1, and the area of the second protruding end face 1311 of the second boss 131 is S22, satisfying: S22 / S1 ≥ 0.8. Optionally, S22 / S1 < 1.3. When the ratio of S22 to S1 is less than 0.8, if the size of the explosion-proof valve 2 remains unchanged, the area of the second protruding end face 1311 of the second boss 131 will be too small, and the effect of relieving deformation will be poor. Concave deformation will still occur in the area of the third side wall 13 other than the second boss 131. Therefore, the ratio of S22 to S1 needs to be greater than or equal to 0.8. When the ratio of S22 to S1 is greater than or equal to 1.3, if the size of the explosion-proof valve 2 remains unchanged, the area of the second protruding end face 1311 of the second boss 131 will be too large, occupying the space of the battery module formation, which is not conducive to the spatial layout of the battery module. Moreover, the flatness of the large surface is difficult to control, the process difficulty increases, and the flatness of the second protruding end face 1311 of the second boss 131 is likely to be unqualified. Therefore, the ratio of S22 to S1 needs to be less than 1.3.

[0054] Optionally, the shape of the first protruding end face 1211 of the first boss 121 is similar to a rectangle, and the two corners of the first boss 121 away from the explosion-proof valve 2 are rounded to cover the concave deformation area on the second side wall 12 to the greatest extent.

[0055] Similarly, optionally, the shape of the second protruding end face 1311 of the second boss 131 is similar to a rectangle, and the two corners of the second boss 131 away from the explosion-proof valve 2 are rounded to cover the concave deformation area on the third side wall 13 to the greatest extent.

[0056] Optionally, along the length direction of the housing body 1, the length of the explosion-proof valve 2 is L, and the length of the first boss 121 is W1, satisfying: L > W1. Under the constraint of the above area ratio range, if the size of the explosion-proof valve 2 remains unchanged, the area of the first protruding end face 1211 of the first boss 121 is within a certain numerical range. If the dimension of the first boss 121 along the length direction of the housing body 1 is too large, the dimension of the first boss 121 along the width direction of the housing body 1 needs to be correspondingly reduced, and the deformation may be transmitted along the width direction of the housing body 1 of the first boss 121 to the area of the second side wall 12 where the first boss 121 is not provided.

[0057] Optionally, along the length direction of the shell body 1, the length of the explosion-proof valve 2 is L, and the length of the second boss 131 is W2, satisfying: L > W2. Similarly, under the constraint of the above area ratio range, if the size of the explosion-proof valve 2 remains unchanged, the area of the second protruding end face 1311 of the second boss 131 is within a certain numerical range. If the dimension of the second boss 131 along the length direction of the shell body 1 is too large, the dimension of the second boss 131 along the width direction of the shell body 1 needs to be correspondingly reduced, and deformation may be transmitted along the width direction of the shell body 1 to the area of the third side wall 13 where the second boss 131 is not provided.

[0058] Optionally, the protruding height H1 of the first boss 121 relative to the second side wall 12 satisfies H1 ≥ 0.25 mm, and optionally, H1 ≤ 0.4 mm. If the protruding height H1 of the first boss 121 relative to the second side wall 12 is less than 0.25 mm, the depth of offsetting the concave deformation is insufficient, and the overall inner concave will still rub against the electrode group. If the protruding height H1 of the first boss 121 relative to the second side wall 12 is greater than 0.4 mm, the first boss 121 protrudes outwards too high, which will occupy the space of the battery core grouping, and the difficulty of controlling the flatness of the first protruding end face 1211 of the first boss 121 will increase, and the probability that the flatness of the first protruding end face 1211 does not meet the requirements will increase.

[0059] Optionally, the protruding height H2 of the second boss 131 relative to the third side wall 13 satisfies H2 ≥ 0.25 mm, and optionally, H2 ≤ 0.4 mm. If the protruding height H2 of the second boss 131 relative to the third side wall 13 is less than 0.25 mm, the depth of offsetting the concave deformation is insufficient, and the overall inner concave will still rub against the electrode group. If the protruding height H2 of the second boss 131 relative to the third side wall 13 is greater than 0.4 mm, the second boss 131 protrudes outwards too high, which will occupy the space of the battery core grouping, and the difficulty of controlling the flatness of the second protruding end face 1311 of the second boss 131 will increase, and the probability that the flatness of the second protruding end face 1311 does not meet the requirements will increase.

[0060] Optionally, the wall thickness T1 of the first boss 121 satisfies T1 ≥ 0.5 mm. The technology in the thin-wall field of the extrusion molding process is not yet mature. In order to ensure the dimensional stability of the shell body 1 and that the pressure resistance of the shell body 1 is greater than 1.2 MPa, the wall thickness T1 of the first boss 121 cannot be less than 0.5 mm.

[0061] Similarly, optionally, the wall thickness T2 of the second boss 131 satisfies T2 ≥ 0.5 mm. The wall thickness T2 of the second boss 131 being greater than or equal to 0.5 mm helps to ensure the dimensional stability of the shell body 1 and that the pressure resistance of the shell body 1 is greater than 1.2 MPa.

[0062] Optionally, in the thickness direction of the housing body 1, the explosion-proof valve 2 is located in the middle of the first side wall 11, and the first boss 121 and the second boss 131 are symmetrically arranged, that is, the shapes, positions, and sizes of the first protruding end face 1211 and the second protruding end face 1311 are the same, the protruding height of the first boss 121 relative to the second side wall 12 is the same as the protruding height of the second boss 131 relative to the third side wall 13, and the wall thickness of the first boss 121 is the same as the wall thickness of the second boss 131.

[0063] In order to verify the effect of this battery cell housing in solving the problem of welding concave deformation, as shown in Tables 1 to 4 below, this embodiment provides the detection records of twenty-three groups of battery cell housings. These twenty-three groups of battery cell housings have some common points. For example, the material of the explosion-proof valve 2 is MXF2, the length of the explosion-proof valve 2 is 68 mm, the width is 15 mm, and the explosion-proof valve 2 and the housing body 1 are fixed by laser welding, and the welding power is 1000 W. It should be noted that the first boss 121 and the second boss 131 of these twenty-three groups of battery cell housings are symmetrically arranged, so the relevant parameters of the first boss 121 and the second boss 131 are not distinguished in the following table. For example, the area of the first protruding end face 1211 of the first boss 121 is S21 and the area of the second protruding end face 1311 of the second boss 131 is S22, both are represented by S2, the dimension W1 of the first boss 121 in the length direction of the housing body 1 and the dimension W2 of the first boss 121 in the length direction of the housing body 1 are both represented by W, the protruding height H1 of the first boss 121 relative to the second side wall 12 and the protruding height H2 of the second boss 131 relative to the third side wall 13 are both represented by H, and the wall thickness T1 of the first boss 121 and the wall thickness T2 of the second boss 131 are both represented by T.

[0064] Table 1 lists the dimensions of the cell housings of six groups of examples, and Table 2 lists the dimensions of the cell housings of six groups of comparative examples. The dimensions of the cell housings of the six groups of examples in Table 1 all meet the above-mentioned more optimal dimension design range. For example, the ratios S2 / S1 of the areas of the protruding end faces of the two bosses to the area of the projection of the explosion-proof valve 2 onto the plane perpendicular to the width direction of the housing body 1 all fall within the range of 0.8 ≤ S2 / S1 < 1.3. Along the length direction of the housing body 1, the lengths W of the two bosses are both less than the length L of the explosion-proof valve 2, the protruding heights H of the two bosses all meet the range of 0.25 mm ≤ H ≤ 0.4 mm, and the wall thicknesses T of the two bosses are both greater than or equal to 5 mm. After welding the explosion-proof valve 2 to the cell housings of these six groups of examples, on the side with the largest area of the housing body 1, that is, the second side wall 12 and the third side wall 13, no out-of-tolerance concave deformation occurs. When the convexity on the back of the concave part protrudes 0.3 mm more than the side wall where no boss is provided, it is called out-of-tolerance concave deformation. Moreover, the welding quality and airtightness detection of the cell housings of these six groups of examples all meet the technical requirements, and the overall yield is greater than 99%. It can be seen that the cell housing that meets the above-mentioned more optimal dimension design specifications can approximately completely avoid the problem of concave deformation, thus ensuring the smooth insertion of the electrode group into the housing, preventing the electrode group from being scratched, and having a high cell yield.

[0065] Table 1

[0066]

[0067]

[0068] The following Table 2 lists the dimensions of the cell housings of six groups of comparative examples. The similarities between the cell housings of these six groups of comparative examples and the six groups of cell housings in Table 1 are the area S1 of the projection of the explosion-proof valve 2 onto the plane perpendicular to the width direction of the housing body 1, the lengths W of the two bosses, the length L of the explosion-proof valve 2, the protruding heights H of the two bosses, and the wall thicknesses T of the two bosses. However, the areas S2 of the protruding end faces of the two bosses of the cell housings of the six groups of comparative examples in Table 2 are different from those of the cell housings of the six groups of examples in Table 1, so the ratio of S2 to S1 is different.

[0069] Specifically, the areas S2 of the protruding end faces of the two bosses of the cell housing of Comparative Example 1 are both 555.66 mm 2, S2 / S1 is only 0.6, which does not meet the above-mentioned more optimal value range of greater than or equal to 0.8. After the explosion-proof valve 2 is welded to the cell housing of this group, the large surfaces of the housing body 1, that is, the second side wall 12 and the third side wall 13, both show out-of-tolerance concave deformation. That is, the convex height of the back surface of the concave is greater than 0.3 mm compared to the side wall where no boss is provided. The welding process meets the technical requirements and the airtightness test is qualified, but the overall yield of the cell housing of this group is only greater than 93%, and it is still difficult to insert the electrode group into the housing, and it is easy to cause rubbing. However, compared with the cell housing without the first boss 121 and the second boss 131, the degree of concavity of the cell housing in Comparative Example 1 is reduced, and the area of the region where the concavity occurs is reduced. Setting the first boss 121 and the second boss 131 can indeed alleviate the problem of the housing body 1 being concave due to welding.

[0070] For the cell housing in Comparative Example 2, the area S2 of the protruding end faces of the two bosses is 611.23 mm 2 , S2 / S1 is only 0.66, which is larger than the ratio in Comparative Example 1, but still does not meet the above-mentioned more optimal value range of greater than or equal to 0.8. After the explosion-proof valve 2 is welded to the cell housing of this group, the large surfaces of the housing body 1, that is, the second side wall 12 and the third side wall 13, also show out-of-tolerance concave deformation. That is, the convex height of the back surface of the concave is greater than 0.3 mm compared to the side wall where no boss is provided. The welding process meets the technical requirements and the airtightness test is qualified, but the overall yield of the cell housing of this group is only greater than 94%, which is slightly higher than that of the cell housing in Comparative Example 1.

[0071] For the cell housing in Comparative Example 3, the area S2 of the protruding end faces of the two bosses is further increased to 648.27 mm 2 , S2 / S1 increases to 0.7, which is larger than the ratio in Comparative Example 2, but still does not meet the above-mentioned more optimal value range of greater than or equal to 0.8. After the explosion-proof valve 2 is welded to the cell housing of this group, the large surfaces of the housing body 1, that is, the second side wall 12 and the third side wall 13, still show out-of-tolerance concave deformation. That is, the convex height of the back surface of the concave is greater than 0.3 mm compared to the side wall where no boss is provided. The welding process meets the technical requirements and the airtightness test is qualified, but the overall yield of the cell housing of this group is only greater than 95%, which is slightly higher than that of the cell housing in Comparative Example 2. It can be seen that in the process of S2 / S1 gradually increasing and approaching 0.8, the overall yield of the cell housing also increases.

[0072] For the cell housing in Comparative Example 4, the area S2 of the protruding end faces of the two bosses is further increased to 722.36 mm 2, S2 / S1 increases to 0.78, which is larger than the ratio of Comparative Example 3 and is very close to the lowest value of 0.8 in the better range. However, after the explosion-proof valve 2 is welded to the cell housing of this group, there is still an out-of-tolerance concave deformation on the large surfaces of the housing body 1, that is, the convex height of the back surface of the concave is greater than the convex height of the side wall where no boss is provided by 0.3 mm. The welding process meets the technical requirements and the airtightness test is qualified. However, the overall yield of the cell housing of this group has increased to about 98%, which is higher than the overall yield of the cell housing of Comparative Example 3. When S2 / S1 is less than 0.8 and the length W of the two bosses remains unchanged, that is, the widths of the two bosses are reduced or the curvature radius at the rounded corners is too large, there will still be some concaves at the positions around the bosses, and the area covered by the bosses is insufficient.

[0073] The areas S2 of the protruding end faces of the two bosses of the cell housing of Comparative Example 5 are further increased, both being 1296.54 mm 2 , S2 / S1 increases to 1.4, that is, it exceeds the better value range. However, after the explosion-proof valve 2 is welded to the cell housing of this group, there is no out-of-tolerance concave deformation on the large surfaces of the housing body 1, that is, the concave deformation problem is completely solved, and the welding process meets the technical requirements and the airtightness test is qualified. However, the areas of the two bosses of the cell housing of this group are too large, which will occupy the space of the cell grouping, and it is difficult to control the flatness of the two protruding end faces with too large areas, increasing the process difficulty. Therefore, when the value of S2 / S1 is greater than or equal to 0.8, the concave deformation problem can be effectively avoided. At this time, ensuring that the value of S2 / S1 is less than 1.3 can further balance the problem of space occupation and reduce the process difficulty of the stamping boss.

[0074] Table 2

[0075] Category Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 <![CDATA[S1 (mm 2 )]]> 926.1 926.1 926.1 926.1 926.1 926.1 <![CDATA[S2(mm 2 )]]> 555.66 611.23 648.27 722.36 1296.54 1065.02 L (mm) 68.00 68.00 68.00 68.00 68.00 68.00 W (mm) 64.50 64.50 64.50 64.50 64.50 64.50 H (mm) 0.30 0.30 0.30 0.30 0.30 0.30 T (mm) 0.5 0.5 0.5 0.5 0.5 0.4 S2 / S1 0.6 0.66 0.7 0.78 1.4 1.15

[0076] Table 3 shows the dimensions of the cell housings of six groups of examples from Example 7 to Example 12, and Table 4 shows the dimensions of the cell housings of five groups of comparative examples from Comparative Example 7 to Comparative Example 11. The dimensions of the cell housings of the six groups of examples in Table 3 all meet the above-mentioned more optimal dimension design range. For example, the ratios S2 / S1 of the areas of the protruding end faces of the two bosses to the area of the projection of the explosion-proof valve 2 onto the plane perpendicular to the width direction of the housing body 1 all fall within the range of 0.8 ≤ S2 / S1 < 1.3. Along the length direction of the housing body 1, the lengths W of the two bosses are both less than the length L of the explosion-proof valve 2, the protruding heights H of the two bosses all meet the range of 0.25 mm ≤ H ≤ 0.4 mm, and the wall thicknesses T of the two bosses are both greater than or equal to 5 mm. After the explosion-proof valve 2 is welded to the cell housings of these six groups of examples, on the side with the largest area of the housing body 1, namely the second side wall 12 and the third side wall 13, no out-of-tolerance concave deformation occurs, and the welding quality and airtightness detection of the cell housings of these six groups of examples all meet the technical requirements, with the overall yield rate being greater than 99%. It can be seen that the cell housing that meets the above-mentioned more optimal dimension design specifications can approximately completely avoid the problem of concave deformation, thus ensuring the smooth insertion of the electrode group into the housing, preventing the electrode group from being scratched, and having a high cell yield rate.

[0077] Table 3

[0078] Category Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 <![CDATA[S1(mm 2 )]]> 926.1 926.1 926.1 926.1 926.1 926.1 <![CDATA[S2(mm 2 )]]> 926.10 926.10 926.10 926.10 926.10 926.10 L (mm) 68.00 68.00 68.00 68.00 68.00 68.00 W (mm) 64.50 64.50 64.50 64.50 64.50 64.50 H (mm) 0.25 0.28 0.30 0.33 0.38 0.40 T (mm) 0.5 0.5 0.5 0.5 0.5 0.5

[0079] Table 4 below shows the dimensions of the cell housings of five groups of comparative examples. The similarities between the cell housings of these five groups of comparative examples and the six groups of cell housings in Table 3 are the area S1 of the projection of the explosion-proof valve 2 onto the plane perpendicular to the width direction of the housing body 1, the areas S2 of the protruding end faces of the two bosses, the lengths W of the two bosses, the length L of the explosion-proof valve 2, and the wall thicknesses T of the two bosses. The difference between the cell housings of the five groups of comparative examples and the six groups of cell housings in Table 3 lies in the protruding height H of the two bosses.

[0080] Specifically, the protruding height H of the two bosses of the battery cell housing in Comparative Example 7 is 0.1 mm for both, which does not reach the lowest value of 0.25 mm in the more optimal value range. After welding the explosion-proof valve 2 to this group of battery cell housings, the large surfaces of the housing body 1, namely the second side wall 12 and the third side wall 13, have out-of-tolerance concave deformation, that is, the convexity of the back surface of the concave is more than 0.3 mm higher than the protruding height of the side wall where no boss is provided. The welding process meets the technical requirements and the airtightness test is qualified, but the overall yield of this group of battery cell housings is less than 92%. It can be seen that when the areas of the two bosses are sufficient, if the protruding height is insufficient, the depth of the concave cannot still be offset, and the effect of strengthening the structural strength by adding the bosses is average. However, compared with the battery cell housing without the first boss 121 and the second boss 131, the degree of concavity of the battery cell housing in Comparative Example 7 is still reduced, and the area of the region with out-of-tolerance concave deformation is decreased. Setting the first boss 121 and the second boss 131 can indeed alleviate the concave problem of the housing body 1 caused by welding.

[0081] The protruding heights H of the two bosses of the battery cell housings in Comparative Examples 8 to 10 gradually increase, being 0.15 mm, 0.18 mm, and 0.23 mm respectively, and the maximum value is very close to the lowest value of 0.25 mm in the more optimal value range. After welding the explosion-proof valve 2 to these three groups of battery cell housings, the large surfaces of the housing body 1, namely the second side wall 12 and the third side wall 13, still have out-of-tolerance concave deformation, that is, the convexity of the back surface of the concave is more than 0.3 mm higher than the protruding height of the side wall where no boss is provided. The welding process meets the technical requirements and the airtightness test is qualified. However, as the protruding height H of the bosses increases, the overall yields of these three groups of battery cell housings gradually increase, being less than 94%, less than 97%, and about 98% respectively. It can be seen that when the areas of the two bosses are sufficient, the closer the protruding height of the two bosses is to 0.25 mm, the more significant the effect of the two bosses in offsetting the concave depth and increasing the structural strength.

[0082] The protruding height H of the two bosses of the battery cell housing in Comparative Example 11 is 0.45 mm for both, that is, it exceeds the maximum value of 0.4 mm in the more optimal value range. After welding the explosion-proof valve 2 to this group of battery cell housings, the large surfaces of the housing body 1, namely the second side wall 12 and the third side wall 13, show no out-of-tolerance concave deformation, that is, the concave problem is completely solved, and the welding process meets the technical requirements and the airtightness test is qualified. However, the two bosses of this group of battery cell housings are too high, which requires more space occupied by the battery cell grouping and is not conducive to the layout setting of the battery module. Moreover, it is difficult to control the flatness of the too-high bosses, and the process difficulty increases. Therefore, when the value of the protruding height H of the two bosses is greater than or equal to 0.25 mm, the concave deformation problem can be effectively avoided. At this time, when the value of the protruding height H of the two bosses is less than or equal to 0.4 mm, the problem of space occupation can be further balanced, and the process difficulty of stamping the bosses can be reduced.

[0083] Table 4

[0084] Category Comparative Example 7 Comparative Example 8 Comparative Example 9 Comparative Example 10 Comparative Example 11 <![CDATA[S1(mm 2 )]]> 926.1 926.1 926.1 926.1 926.1 <![CDATA[S2(mm 2 )]]> 926.10 926.10 926.10 926.10 926.10 L (mm) 68.00 68.00 68.00 68.00 68.00 W (mm) 64.50 64.50 64.50 64.50 64.50 H (mm) 0.10 0.15 0.18 0.23 0.45 T (mm) 0.5 0.5 0.5 0.5 0.5

[0085] Optionally, an explosion-proof groove is formed on the outer side of the first side wall 11, and an explosion-proof through hole 111 is formed at the bottom of the explosion-proof groove. The explosion-proof valve 2 is located in the explosion-proof groove, which is convenient for assembling and welding the explosion-proof valve 2, and the notch of the explosion-proof valve 2 is within the range of the explosion-proof through hole 111.

[0086] An explosion-proof valve 2 is provided on the battery cell housing. When the battery cell is thermally out of control, the path of opening the valve for exhaust is shorter, which can improve the safety performance of the battery cell. Moreover, the housing body 1 of the battery cell housing is formed by extrusion molding, and the design of inner wall stamping bosses is adopted for the two large surfaces adjacent to the side where the explosion-proof valve 2 is welded. On the one hand, it can improve the structural strength and relieve the concave deformation. On the other hand, it can directly offset the concave depth and prevent the pole group from being scratched during the assembly of the pole group. And the boss is arranged near the position where the explosion-proof valve 2 is welded, which can avoid causing space limitation to the battery cell coating and the battery cell grouping. And through the optimized dimension design of the battery cell housing in this embodiment, the problem of concave deformation caused by welding can be completely solved, and the yield of the battery cell can be improved.

[0087] This embodiment also provides a battery cell, which includes a pole group, a battery cell top cover 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 a housing, and the pole group is located inside the housing. This battery cell can help reduce the degree of scratching of the pole group when it enters the housing, thereby improving the yield of the battery cell.

[0088] Obviously, the above-mentioned embodiments of the present invention are only examples for clearly explaining the present invention, rather than limitations on 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 on the basis of the above description. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent replacements, 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. The battery cell housing, characterized in that, Comprising: A housing body (1), the housing body (1) includes a first side wall (11), and a second side wall (12) and a third side wall (13) oppositely arranged along its own thickness direction. The second side wall (12) has a first boss (121) formed by stamping and protruding outward, and the third side wall (13) has a second boss (131) formed by stamping and protruding outward; An explosion-proof valve (2), the explosion-proof valve (2) is welded to the first side wall (11). Both the first boss (121) and the second boss (131) are arranged close to the explosion-proof valve (2), so that the deformation caused by the welding of the explosion-proof valve (2) is at least partially located at the first boss (121) and the second boss (131).

2. The cell housing according to claim 1, wherein One side of the first boss (121) coincides with the side between the second side wall (12) and the first side wall (11); And / or, one side of the second boss (131) coincides with the side between the third side wall (13) and the first side wall (11).

3. The cell housing according to claim 1, wherein The explosion-proof valve (2) is located in the middle of the first side wall (11) along a first direction, and the first direction is the length direction of the housing body (1). The first boss (121) is located in the middle of the second side wall (12) along the first direction, and / or, the second boss (131) is located in the middle of the third side wall (13) along the first direction.

4. The cell housing according to claim 1, characterized in that, The area of the projection of the explosion-proof valve (2) onto a plane perpendicular to the width direction of the housing body (1) is S1, and the area of the first protruding end face (1211) of the first boss (121) is S21, satisfying: S21 / S1≥0.8, and / or, S21 / S1<1.3; And / or, the area of the projection of the explosion-proof valve (2) onto a plane perpendicular to the width direction of the housing body (1) is S1, and the area of the second protruding end face (1311) of the second boss (131) is S22, satisfying: S22 / S1≥0.8, and / or, S22 / S1<1.

3.

5. The cell housing according to claim 4, wherein Along the length direction of the housing body (1), the length of the explosion-proof valve (2) is L, and the length of the first boss (121) is W1, satisfying: L>W1; And / or, along the length direction of the housing body (1), the length of the explosion-proof valve (2) is L, and the length of the second boss (131) is W2, satisfying: L>W2.

6. The cell housing according to any one of claims 1-5, characterized in that, The protruding height H1 of the first boss (121) compared to the second side wall (12) satisfies H1≥0.25mm, and / or, H1≤0.4mm; The protruding height H2 of the second boss (131) compared to the third side wall (13) satisfies H2≥0.25mm, and / or, H2≤0.4mm.

7. The cell housing according to any one of claims 1-5, characterized in that, The wall thickness T1 of the first boss (121) satisfies T1≥0.5mm; And / or, the wall thickness T2 of the second boss (131) satisfies T2≥0.5mm.

8. The cell housing according to any one of claims 1-5, characterized in that, In the thickness direction of the shell body (1), the explosion-proof valve (2) is located in the middle of the first side wall (11), and the first boss (121) and the second boss (131) are symmetrically arranged.

9. The cell housing according to any one of claims 1-5, characterized in that, An explosion-proof groove is formed on the outer side of the first side wall (11), and an explosion-proof through hole (111) is formed at the bottom of the explosion-proof groove. The explosion-proof valve (2) is located in the explosion-proof groove, and the notch of the explosion-proof valve (2) is within the range of the explosion-proof through hole (111).

10. The battery cell is characterized in that, It includes a pole group, a battery cell top cover, 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 an outer shell, and the pole group is located inside the outer shell.

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