Explosion-proof shell and battery cell

Abstract

The invention relates to the technical field of energy storage equipment, in particular to an explosion-proof shell and a battery cell, and the explosion-proof shell comprises a shell body and an explosion-proof valve. The shell body is provided with a first side wall, a third side wall and a second side wall which are sequentially connected, the first side wall and the second side wall are oppositely arranged in the thickness direction of the shell body, and the third side wall is located at one end of the shell body in the width direction. An anti-explosion through hole is formed in the third side wall, and the wall thickness of the first side wall and the wall thickness of the second side wall are both smaller than the wall thickness of the third side wall. The first side wall is provided with a first variable wall area close to the third side wall, and the wall thickness of the first variable wall area close to the third side wall is thicker. The second side wall is provided with a second variable wall area close to the third side wall, the wall thickness of the second variable wall area close to the third side wall is larger, and the anti-explosion valve is welded to the third side wall and blocks the anti-explosion through hole. The battery cell comprises a battery cell top cover, a pole group and the explosion-proof shell, the battery cell top cover covers the opening of the explosion-proof shell in a sealing manner to form a shell of the battery cell, and the pole group is arranged in the shell.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage equipment, and in particular to an explosion-proof housing and a battery core. Background Art

[0002] To improve battery cell safety, existing technology generally incorporates an explosion-proof valve on the cell cover. This allows for the targeted release of high-temperature gases from the cell in the event of thermal runaway, preventing explosion. However, because the cell cover is located at one end of the cell's length, the gas path to the explosion-proof valve is long, which is detrimental to improving cell safety. Placing the explosion-proof valve on the sidewall of the cell's housing shortens the exhaust path and improves safety. However, the housing has a thinner wall than the cell cover, and a hole is required to accommodate the explosion-proof valve. This weakens the housing structure where the explosion-proof valve is welded, making welding susceptible to deformation, impacting subsequent assembly and use of the cell. Furthermore, welding the explosion-proof valve to the housing prevents the heat generated from dissipating quickly, further exacerbating deformation in the high-temperature environment. These issues also increase welding process requirements, reduce process yield, increase production costs, and reduce production efficiency. Summary of the Invention

[0003] An object of the present invention is to provide an explosion-proof housing that can help alleviate the problem of housing body deformation and improve process yield and production efficiency.

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

[0005] Provided is an explosion-proof housing, comprising:

[0006] The shell body comprises a first side wall, a third side wall and a second side wall connected in sequence, the first side wall and the second side wall being arranged opposite to each other along the thickness direction of the shell body, the third side wall being located at one end in the width direction of the shell body, the third side wall being provided with an explosion-proof through hole, the wall thickness of the first side wall and the wall thickness of the second side wall being less than the wall thickness of the third side wall, the first side wall having a first variable wall region, the first variable wall region being arranged close to the third side wall, the wall thickness of the first variable wall region being thicker as it is closer to the third side wall, the second side wall having a second variable wall region, the second variable wall region being arranged close to the third side wall, the wall thickness of the second variable wall region being thicker as it is closer to the third side wall;

[0007] An explosion-proof valve is welded to the third side wall and blocks the explosion-proof through hole.

[0008] Optionally, the wall thickness T21 of the first side wall where the first wall-changing region is not provided satisfies T21 ≥ 0.45 mm;

[0009] And / or, the wall thickness T22 of the second side wall where the second wall-changing region is not provided satisfies T22 ≥ 0.45 mm.

[0010] Optionally, the wall thickness T21 of the first sidewall where the first wall-changing region is not provided and the wall thickness T1 of the third sidewall satisfy 0.42≤T21 / T1≤0.6;

[0011] And / or, the wall thickness T22 of the second side wall where the second wall-changing region is not provided and the wall thickness T1 of the third side wall satisfy 0.42≤T22 / T1≤0.6.

[0012] Optionally, a dimension W1 of the first variable wall region along the width direction of the shell body satisfies: W1 ≥ 8 mm;

[0013] A dimension W2 of the second variable wall region along the width direction of the shell body satisfies W2 ≥ 8 mm.

[0014] Optionally, along the width direction of the third side wall, a vertical distance H1 between an edge of the explosion-proof valve close to the first side wall and the first side wall satisfies: H1 ≥ 2.8 mm;

[0015] And / or, along the width direction of the third side wall, a vertical distance H2 between an edge of the explosion-proof valve close to the second side wall and the second side wall satisfies: H2 ≥ 2.8 mm.

[0016] Optionally, a dimension of the first variable wall region along the width direction of the shell body is W1, and a vertical distance between an edge of the explosion-proof valve close to the first side wall and the first side wall along the width direction of the third side wall is H1, satisfying 0.35≤H1 / W1≤0.63;

[0017] And / or, the dimension of the second variable wall area along the width direction of the shell body is W2, and along the width direction of the third side wall, the vertical distance between the edge of the explosion-proof valve close to the second side wall and the second side wall is H2, satisfying 0.35≤H2 / W2≤0.63.

[0018] Optionally, the first variable wall region passes through the first side wall along the length direction of the shell body;

[0019] And / or, the second variable wall region passes through the second side wall along the length direction of the shell body.

[0020] Optionally, the first wall-changing region has a first inclined surface, the first inclined surface is located at the inner wall of the shell body, and an obtuse angle is formed between the first inclined surface and the inner wall surface of the first side wall where the first wall-changing region is not provided;

[0021] And / or, the second wall-changing region has a second inclined surface, the second inclined surface is located at the inner wall of the shell body, and an obtuse angle is formed between the second inclined surface and the inner wall surface of the second sidewall where the second wall-changing region is not provided.

[0022] Optionally, a limiting groove is provided on the outward end surface of the third side wall, the explosion-proof through hole is provided at the bottom of the limiting groove, and the explosion-proof valve is located in the limiting groove.

[0023] Another object of the present invention is to provide a battery cell that can help alleviate the problem of shell body deformation and improve process yield and production efficiency.

[0024] To achieve this object, the present invention adopts the following technical solutions:

[0025] Provided is a battery cell, comprising a battery cell top cover, a pole group and the above-mentioned explosion-proof shell, wherein the battery cell top cover sealing cover is arranged at the opening of the explosion-proof shell to form an outer shell of the battery cell, and the pole group is arranged in the outer shell.

[0026] Beneficial effects of the present invention:

[0027] The present invention provides an explosion-proof housing, comprising a housing body and an explosion-proof valve. The housing body comprises a first sidewall, a third sidewall, and a second sidewall, which are sequentially connected. The first and second sidewalls are arranged opposite each other along the thickness direction of the housing body, with the third sidewall located at one end of the housing body in the width direction. The third sidewall defines an explosion-proof through-hole. The thickness of the first and second sidewalls is less than that of the third sidewall. The first sidewall comprises a first variable wall region, which is disposed proximate to the third sidewall, with the thickness of the first variable wall region increasing as it approaches the third sidewall. The second sidewall comprises a second variable wall region, which is disposed proximate to the third sidewall, with the thickness of the second variable wall region increasing as it approaches the third sidewall. The explosion-proof valve is welded to the third sidewall and blocks the explosion-proof through-hole. The placement of the first variable wall region proximate to the third sidewall provides the first variable wall region with increased structural strength, with the first variable wall region increasing in strength as it approaches the third sidewall. The first variable wall region prevents deformation caused by welding the explosion-proof valve to the third sidewall from being transmitted to locations on the first sidewall where the first variable wall region is not disposed. Similarly, by providing a second variable wall region near the second sidewall and the third sidewall, the second variable wall region has a higher structural strength, and the closer the second variable wall region is to the third sidewall, the higher the structural strength. This second variable wall region prevents deformation caused by welding the explosion-proof valve on the third sidewall from being transmitted to the portion of the second sidewall where the second variable wall region is not provided. Therefore, this explosion-proof enclosure can alleviate deformation caused by welding on the first, second, and third sidewalls of the enclosure body, resulting in higher process yield and production efficiency.

[0028] The present invention also provides a battery cell comprising a battery cell top cover, a pole group, and the aforementioned explosion-proof housing. The battery cell top cover sealing cover is disposed at the opening of the explosion-proof housing to form the battery cell outer shell, and the pole group is disposed within the outer shell. This battery cell can help alleviate the problem of housing deformation, thereby improving process yield and production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the exploded structure of the explosion-proof housing provided by an embodiment of the present invention;

[0030] Figure 2 Schematic diagram of the structure of the explosion-proof housing provided by an embodiment of the present invention;

[0031] Figure 3 yes Figure 2 Middle AA section view;

[0032] Figure 4 yes Figure 3 Enlarged view of point B in the middle.

[0033] In the picture:

[0034] 1. Shell body; 11. First side wall; 111. First variable wall region; 1111. First inclined surface; 12. Second side wall; 121. Second variable wall region; 1211. Second inclined surface; 13. Third side wall; 131. Explosion-proof through hole; 132. Limiting groove;

[0035] 2. Explosion-proof valve; 3. Welding position. DETAILED DESCRIPTION

[0036] Before any embodiments of the present application are explained in detail, it is to be understood that the application is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the foregoing drawings.

[0037] In this application, the terms "comprises," "includes," "has," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0038] In this application, the term "and / or" describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Additionally, the character " / " in this application generally indicates that the related objects are in an "and / or" relationship.

[0039] In this application, the terms "connect," "combine," "couple," and "install" may refer to direct connection, combination, coupling, or installation, or indirect connection, combination, coupling, or installation. For example, a direct connection refers to two parts or components being connected together without an intermediary, and an indirect connection refers to two parts or components being connected to at least one intermediary, with the two parts or components being connected via the intermediary. Furthermore, "connect" and "couple" are not limited to physical or mechanical connections or couplings and may include electrical connections or couplings.

[0040] In this application, it will be understood by those skilled in the art that relative terms (e.g., "about," "approximately," "substantially," etc.) used in conjunction with quantities or conditions include the values and have the meaning indicated by the context. For example, the relative terms include at least the degree of error associated with the measurement of a specific value, the tolerance caused by manufacturing, assembly, use, etc. associated with a specific value. Such terms should also be considered to disclose a range defined by the absolute values of the two endpoints. 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 use relative terms should also be disclosed as specific values with tolerances. In addition, "substantially" may refer to plus or minus a certain degree (e.g., 1 degree, 5 degrees, 10 degrees or more) on the basis of the indicated angle when expressing a relative angular position relationship (e.g., substantially parallel, substantially perpendicular).

[0041] In this application, it will be understood by those skilled in the art that the function performed by an assembly can be performed by one assembly, multiple assemblies, one part, or multiple parts. Similarly, the function performed by a part can also be performed by one part, one assembly, or a combination of multiple parts.

[0042] In the present application, the terms "upper", "lower", "left", "right", "front", "back" and other directional words are described based on the orientation and positional relationship shown in the accompanying drawings, and should not be understood as limiting the embodiments of the present application. In addition, in the context, it is also necessary to understand that when it is mentioned that an element is connected to another element "upper" or "lower", it can not only be directly connected to the other element "upper" or "lower", but also be indirectly connected to the other element "upper" or "lower" through an intermediate element. It should also be understood that directional words such as upper side, lower side, left side, right side, front side, back side, etc. not only represent the positive orientation, but can also be understood as the lateral orientation. For example, below can include directly below, lower left, lower right, lower front and lower back, etc.

[0043] To improve battery cell safety, existing technology generally incorporates an explosion-proof valve on the cell cover. This allows for the targeted release of high-temperature gases from the cell in the event of thermal runaway, preventing explosion. However, because the cell cover is located at one end of the cell's length, the gas path to the explosion-proof valve is long, which is detrimental to improving cell safety. Placing the explosion-proof valve on the sidewall of the cell's housing shortens the exhaust path and improves safety. However, the housing has a thinner wall than the cell cover, and a hole is required to accommodate the explosion-proof valve. This weakens the housing structure where the explosion-proof valve is welded, making welding susceptible to deformation, impacting subsequent assembly and use of the cell. Furthermore, welding the explosion-proof valve to the housing prevents the heat generated from dissipating quickly, further exacerbating deformation in the high-temperature environment. These issues also increase welding process requirements, reduce process yield, increase production costs, and reduce production efficiency.

[0044] This embodiment provides an explosion-proof housing to solve the above-mentioned problem. The explosion-proof housing can help alleviate the deformation problem of the housing body 1 and improve the process yield and production efficiency.

[0045] like Figures 1-4 As shown, the explosion-proof housing of this embodiment includes a housing body 1 and an explosion-proof valve 2. The housing body 1 has a first sidewall 11, a third sidewall 13, and a second sidewall 12, which are sequentially connected. The first sidewall 11 and the second sidewall 12 are arranged opposite each other along the thickness direction of the housing body 1, and the third sidewall 13 is located at one end of the width direction of the housing body 1. The third sidewall 13 defines an explosion-proof through-hole 131. The thickness of the first sidewall 11 and the second sidewall 12 are both less than that of the third sidewall 13. The first sidewall 11 has a first variable wall region 111, which is located proximate to the third sidewall 13 and has a thickness that increases as the first variable wall region 111 approaches the third sidewall 13. The second sidewall 12 has a second variable wall region 121, which is located proximate to the third sidewall 13 and has a thickness that increases as the second variable wall region 121 approaches the third sidewall 13. The explosion-proof valve 2 is welded to the third sidewall 13 and blocks the explosion-proof through-hole 131.

[0046] A first variable wall region 111 is provided near the first side wall 11 and the third side wall 13. The first variable wall region 111 has a high structural strength, and the closer the first variable wall region 111 is to the third side wall 13, the higher the structural strength. This prevents deformation caused by welding the explosion-proof valve 2 on the third side wall 13 from being transmitted to portions of the first side wall 11 where the first variable wall region 111 is not provided. Similarly, a second variable wall region 121 is provided near the second side wall 12 and the third side wall 13. The second variable wall region 121 has a high structural strength, and the closer the second variable wall region 121 is to the third side wall 13, the higher the structural strength. This prevents deformation caused by welding the explosion-proof valve 2 on the third side wall 13 from being transmitted to portions of the second side wall 12 where the second variable wall region 121 is not provided. The provision of the first and second variable wall regions 111 and 121 eliminates the need to increase the overall wall thickness of the first and second side walls 11 and 12, thereby avoiding a significant increase in the weight of the housing 1 and preventing excessive impact on the space for electrode assembly arrangement. Therefore, the explosion-proof housing can alleviate the deformation problem of the first side wall 11, the second side wall 12 and the third side wall 13 of the housing body 1 caused by welding, and has higher process yield and production efficiency.

[0047] Optionally, the shell body 1 is extruded to ensure that the structural strength and airtightness of the joints of the various walls meet quality requirements. In addition, extrusion molding can easily produce two areas with varying wall thicknesses, the first variable wall area 111 and the second variable wall area 121, to ensure production efficiency.

[0048] Alternatively, as Figure 4 As shown, the wall thickness T21 of the first side wall 11 where the first wall variable area 111 is not provided meets the requirement of T21 ≥ 0.45 mm to ensure the structural strength of the first side wall 11 where the first wall variable area 111 is not provided. If the wall thickness here is less than 0.45 mm, it is easy to be slightly affected by the welding explosion-proof valve 2 on the third side wall 13 and deform.

[0049] Optionally, the wall thickness T22 of the second side wall 12 where the second variable wall area 121 is not provided satisfies T22 ≥ 0.45 mm to ensure the structural strength of the second side wall 12 where the second variable wall area 121 is not provided. If the wall thickness here is less than 0.45 mm, it is also susceptible to slight deformation due to the welding of the explosion-proof valve 2 on the third side wall 13.

[0050] Optionally, the wall thickness T21 of the first side wall 11 where the first wall variable region 111 is not provided and the wall thickness T1 of the third side wall 13 satisfy 0.42≤T21 / T1≤0.6. It should be noted that the wall thickness T1 of the third side wall 13 here refers to the wall thickness of the third side wall 13 where the limiting groove 132 is not provided. When the ratio of the wall thickness T21 of the first side wall 11 where the first wall variable region 111 is not provided and the wall thickness T1 of the third side wall 13 is less than 0.42, the difference between the two is too large. If the wall thickness T1 of the third side wall 13 remains unchanged, the wall thickness T21 of the first side wall 11 where the first wall variable region 111 is not provided is too small, and deformation is still likely to occur at the first side wall 11, but the deformation at the third side wall 13 is reduced, and the air tightness at the explosion-proof valve 2 meets the requirements. If the wall thickness T21 of the first side wall 11 where the first wall variable region 111 is not provided remains unchanged, the wall thickness T1 of the third side wall 13 will be too large, resulting in excessive weight and space occupation of the third side wall 13. If the ratio of the wall thickness T21 of the first side wall 11 where the first wall variable region 111 is not provided to the wall thickness T1 of the third side wall 13 is greater than 0.6, the difference between the two is too small. In order to ensure a sufficient thickness of the third side wall 13, the wall thickness T21 of the first side wall 11 where the first wall variable region 111 is not provided needs to be increased accordingly. However, if the wall thickness of the large side wall of the shell body 1 is too large, the material cost and weight of the shell body 1 will increase significantly, and it will be unfavorable for the arrangement of the electrode group.

[0051] Optionally, the wall thickness T22 of the second side wall 12 where the second variable wall region 121 is not provided and the wall thickness T1 of the third side wall 13 satisfy the following: 0.42≤T22 / T1≤0.6. Similarly, when the ratio of the wall thickness T22 of the second side wall 12 where the second variable wall region 121 is not provided and the wall thickness T1 of the third side wall 13 is less than 0.42, the difference between the two is too large. If the wall thickness T1 of the third side wall 13 remains unchanged, the wall thickness T22 of the second side wall 12 where the second variable wall region 121 is not provided is too small, and deformation of the second side wall 12 is still likely to occur. However, the deformation of the third side wall 13 is reduced, and the airtightness of the explosion-proof valve 2 meets the requirements. If the wall thickness T22 of the second side wall 12 where the second variable wall region 121 is not provided remains unchanged, the wall thickness T1 of the third side wall 13 will be too large, resulting in excessive weight and space occupied by the third side wall 13. When the ratio of the wall thickness T22 of the second side wall 12 where the second wall variable region 121 is not provided and the wall thickness T1 of the third side wall 13 is greater than 0.6, the difference between the two is too small. In order to ensure that the wall thickness T1 of the third side wall 13 is large enough, the wall thickness T22 of the second side wall 12 where the second wall variable region 121 is not provided needs to be increased accordingly. However, if the wall thickness of the large side wall of the shell body 1 is too large, the material cost and weight of the shell body 1 will increase too much, and it will be unfavorable for the arrangement of the pole group.

[0052] Optionally, in this embodiment, the first variable wall region 111 passes through the first side wall 11 along the length direction of the shell body 1 to facilitate processing. Of course, in other embodiments, the first variable wall region 111 can also be provided only near the location of the explosion-proof valve 2.

[0053] Optionally, the second variable wall region 121 extends through the second side wall 12 along the length of the shell body 1. In this embodiment, the second variable wall region 121 extends through the second side wall 12 along the length of the shell body 1 to facilitate processing. Of course, in other embodiments, the second variable wall region 121 may also be provided only near the location of the explosion-proof valve 2.

[0054] like Figure 4 As shown, optionally, the first variable wall region 111 has a first inclined surface 1111, and the first inclined surface 1111 is located on the inner wall of the shell body 1. The first inclined surface 1111 forms an obtuse angle with the inner wall surface of the first side wall 11 where the first variable wall region 111 is not provided. Optionally, the outer wall surface of the first variable wall region 111 is flush with the outer wall surface of the first side wall 11 where the first variable wall region 111 is not provided, to prevent the battery cells from being arranged in groups. In addition, the first inclined surface 1111 can also prevent the pole group from being completely close to the third side wall 13 to a certain extent, thereby preventing the explosion-proof through hole 131 from being blocked on the inside, thereby affecting the safety of the battery cells.

[0055] Optionally, the second variable wall region 121 has a second inclined surface 1211, and the second inclined surface 1211 is located at the inner wall of the shell body 1, and an obtuse angle is formed between the second inclined surface 1211 and the inner wall surface of the second side wall 12 where the second variable wall region 121 is not provided. Optionally, the outer wall surface of the second variable wall region 121 is flush with the outer wall surface of the second side wall 12 where the second variable wall region 121 is not provided, so as to prevent the battery cells from being difficult to arrange when grouped. In addition, the distance between the second inclined surface 1211 and the first inclined surface 1111 is smaller the closer to the third side wall 13, which can prevent the pole group from being completely close to the third side wall 13 to a certain extent, thereby preventing the explosion-proof through-hole 131 from being blocked on the inside, thereby affecting the safety of the battery cells.

[0056] Optionally, the dimension W1 of the first variable wall region 111 along the width direction of the shell body 1 satisfies, W1 ≥ 8 mm. It should be noted that when measuring the dimension W1 of the first variable wall region 111 along the width direction of the shell body 1, one end is the boundary between the first inclined surface 1111 and the inner wall of the first side wall 11 where the first variable wall region 111 is not provided, and the other end is the extension surface of the outer wall surface of the third side wall 13, and the distance between the two ends along the width direction of the shell body 1 is W1. Optionally, in this embodiment, the W1 value of the first variable wall region 111 at each location along the length direction of the shell body 1 remains unchanged. When W1 is less than 8 mm, that is, the first variable wall region 111 is too short, the position of the first side wall 11 where the first variable wall region 111 is not provided and close to the first variable wall region 111 and the position where the wall thickness of the first variable wall region 111 is thinner will still deform, but the severity of the deformation is lower.

[0057] Optionally, the dimension W2 of the second variable wall region 121 along the width direction of the shell body 1 satisfies, W2 ≥ 8mm. It should be noted that, when measuring the dimension W2 of the second variable wall region 121 along the width direction of the shell body 1, one end is the boundary between the second inclined surface 1211 and the inner wall of the second side wall 12 where the second variable wall region 121 is not provided, and the other end is the extension surface of the outer wall surface of the third side wall 13, and the distance between the two ends along the width direction of the shell body 1 is W2. Optionally, in this embodiment, the W2 value of the second variable wall region 121 at each location along the length direction of the shell body 1 remains unchanged. When W2 is less than 8mm, that is, the second variable wall region 121 is too short, the position of the second side wall 12 where the second variable wall region 121 is not provided and close to the second variable wall region 121 and the position where the wall thickness of the second variable wall region 121 is thinner will still deform, but the severity of the deformation is lower.

[0058] Optionally, in this embodiment, the wall thickness T21 of the first sidewall 11 where the first wall variable region 111 is not provided is the same as the wall thickness T22 of the second sidewall 12 where the second wall variable region 121 is not provided. Optionally, the dimension W1 of the first wall variable region 111 along the width direction of the shell body 1 and the dimension W2 of the second wall variable region 121 along the width direction of the shell body 1 are the same, that is, the first sidewall 11 and the second sidewall 12 are arranged in mirror symmetry.

[0059] Optionally, along the width direction of the third side wall 13, the vertical distance H1 between the edge of the explosion-proof valve 2 close to the first side wall 11 and the first side wall 11 satisfies, H1 ≥ 2.8 mm. It should be noted that when measuring the vertical distance H1 between the edge of the explosion-proof valve 2 close to the first side wall 11 and the first side wall 11, one end is the edge of the explosion-proof valve 2 close to the first side wall 11, and the other end is the extension surface of the outer wall surface of the first side wall 11. The distance between the two ends along the thickness direction of the shell body 1 is H1. When H1 is less than 2.8 mm, the edge of the explosion-proof valve 2 is too close to the first side wall 11, and the impact of the welding of the explosion-proof valve 2 on the first side wall 11 is too large. On the basis of setting the first variable wall area 111 on the first side wall 11, it is still easy to affect the flatness of the first side wall 11.

[0060] Optionally, along the width direction of the third side wall 13, the vertical distance H2 between the edge of the explosion-proof valve 2 close to the second side wall 12 and the second side wall 12 satisfies, H2 ≥ 2.8 mm. It should be noted that when measuring the vertical distance H2 between the edge of the explosion-proof valve 2 close to the second side wall 12 and the second side wall 12, one end is the edge of the explosion-proof valve 2 close to the second side wall 12, and the other end is the extension surface of the outer wall surface of the second side wall 12. The distance between the two ends along the thickness direction of the shell body 1 is H2. When H2 is less than 2.8 mm, the edge of the explosion-proof valve 2 is too close to the second side wall 12, and the impact of the welding of the explosion-proof valve 2 on the second side wall 12 is too large. On the basis of setting the second variable wall area 121 on the second side wall 12, it is still easy to affect the flatness of the second side wall 12.

[0061] Optionally, the dimension W1 of the first variable wall region 111 along the width direction of the shell body 1 and the vertical distance H1 between the edge of the explosion-proof valve 2 close to the first side wall 11 and the first side wall 11 along the width direction of the third side wall 13 satisfy 0.35≤H1 / W1≤0.63. When the ratio of H1 to W1 is less than 0.35 and H1 remains unchanged, W1 will be too large, resulting in the first variable wall region 111 being too wide. When W1 is greater than or equal to 8 mm and other parameters fall within a more optimal value range, it is ensured that the first side wall 11 will no longer undergo excessive deformation. Therefore, further increasing W1 will only increase the weight of the first side wall 11 and the cost of the explosion-proof shell. When the ratio of H1 to W1 is greater than 0.63 and W1 remains unchanged, H1 will be too large, resulting in the width of the third side wall 13 being too large, or the explosion-proof valve 2 being too narrow, which is not conducive to the arrangement of the third side wall 13. When the explosion-proof valve 2 is too narrow, the welding position 3 is too close to the notch position of the explosion-proof valve 2, which will also increase the difficulty of welding and affect the blasting accuracy of the explosion-proof valve 2.

[0062] Optionally, the dimension W2 of the second variable wall region 121 along the width direction of the shell body 1 and the vertical distance H2 between the edge of the explosion-proof valve 2 near the second side wall 12 and the second side wall 12 along the width direction of the third side wall 13 satisfy 0.35≤H2 / W2≤0.63. When the ratio of H2 to W2 is less than 0.35 and H2 remains unchanged, W2 will be too large, resulting in the second variable wall region 121 being too wide. When W2 is greater than or equal to 8 mm and other parameters fall within a more optimal value range, it is guaranteed that the second side wall 12 will no longer undergo excessive deformation. Therefore, further increasing W2 will only increase the weight of the second side wall 12 and the cost of the explosion-proof shell. When the ratio of H2 to W2 is greater than 0.63 and W2 remains unchanged, H2 will be too large, resulting in the width of the third side wall 13 being too large, or the explosion-proof valve 2 being too narrow, which is not conducive to the arrangement of the third side wall 13. When the explosion-proof valve 2 is too narrow, the welding position 3 is too close to the notch position of the explosion-proof valve 2, which will also increase the difficulty of welding and affect the blasting accuracy of the explosion-proof valve 2.

[0063] Optionally, the vertical distance H1 between the edge of the explosion-proof valve 2 close to the first side wall 11 and the first side wall 11 is consistent with the vertical distance H2 between the edge of the explosion-proof valve 2 close to the second side wall 12 and the second side wall 12, that is, along the thickness direction of the shell body 1, the explosion-proof valve 2 is located in the middle of the third side wall 13.

[0064] Optionally, a limiting groove 132 is provided on the outward end surface of the third side wall 13 , the explosion-proof through hole 131 is provided at the bottom of the limiting groove 132 , and the explosion-proof valve 2 is located in the limiting groove 132 to facilitate assembly and positioning of the explosion-proof valve 2 .

[0065] In order to verify whether the explosion-proof housing can alleviate the deformation problem of the shell body 1, improve the process yield and production efficiency, and the influence of the ratio of T2 to T1 on the performance of the explosion-proof housing, as shown in Tables 1 and 2 below, this embodiment provides six groups of examples and five groups of comparative examples of explosion-proof housings, and tests are performed on them. The similarities between the explosion-proof shells of the six groups of examples and the five groups of comparative examples are that: the material of the explosion-proof valve 2 is MXF2, the length of the explosion-proof valve 2 is 50 mm, the width is 14 mm, the shell body 1 is extruded from three-series aluminum, the size W1 of the first variable wall area 111 along the width direction of the shell body 1 and the size W2 of the second variable wall area 121 along the width direction of the shell body 1 are the same, both represented by W, and the value of W is 8 mm, the vertical distance H1 between the edge of the explosion-proof valve 2 close to the first side wall 11 and the first side wall 11 and the vertical distance H2 between the edge of the explosion-proof valve 2 close to the second side wall 12 and the second side wall 12 are the same, both represented by H, and the value of H is 5 mm, in addition, the wall thickness T21 at the first side wall 11 where the first variable wall area 111 is not set and the wall thickness T22 at the second side wall 12 where the second variable wall area 121 is not set are the same, both represented by T2, that is, the first side wall 11 and the second side wall 12 are mirror-symmetrically arranged.

[0066] Specifically, Table 1 below shows the dimensional parameters of six sets of examples, all of which meet the aforementioned optimal ranges, for example: 0.42 ≤ T2 / T1 ≤ 0.6, T2 ≥ 0.45 mm, W ≥ 8 mm, H ≥ 2.8 mm, and 0.35 ≤ H / W ≤ 0.63. Testing showed that none of the six sets of explosion-proof housings exhibited excessive deformation on the first and second sidewalls 11, 12. The electrode assembly insertion into the housing was scratch-free. The welding of the explosion-proof valve 2 on the third sidewall 13 met technical requirements, as did the airtightness test results. The overall yield rate of the battery cells exceeded 99%. It can be seen that respectively setting variable wall areas at the first side wall 11 and the second side wall 12 can effectively alleviate the deformation problem of the shell body 1 caused by welding the explosion-proof valve 2, and when the size of the explosion-proof shell meets the above-mentioned better value range, the explosion-proof shell can completely avoid the deformation problem, and the blasting stability of the explosion-proof valve 2 and the airtightness of the explosion-proof shell meet the technical requirements, and the process yield and production efficiency of the battery cell can be improved.

[0067] As shown in Table 2, the wall thickness T21 of the first sidewall 11 of the explosion-proof housing in Comparative Example 1, where the first variable wall region 111 is not provided, and the wall thickness T22 of the second sidewall 12, where the second variable wall region 121 is not provided, are both 0.35 mm, less than the minimum value of the optimal value range. This indicates that the first and second sidewalls 11 and 12 are too thin. Furthermore, the ratio of T2 to T1 is 0.35, also less than the minimum value of the optimal value range. This indicates that deformation is primarily concentrated in the first and second sidewalls 11 and 12. Testing showed that the welding of the explosion-proof valve 2 at the third sidewall 13 of this explosion-proof housing met technical requirements, as did the airtightness test results. However, the first and second sidewalls 11 and 12 exhibited significant excessive deformation, resulting in scratches when the electrode assembly was inserted into the housing. The overall yield rate of the battery cells was less than 92%. However, it should be noted that the degree of deformation of this explosion-proof housing was lower than that of the prior art explosion-proof housing without a variable wall region. This indicates that the provision of a variable wall region can still alleviate the deformation problem to a certain extent.

[0068] As shown in Table 2, the wall thickness T21 of the first sidewall 11 of the explosion-proof housing in Comparative Example 2, where the first variable wall region 111 is not provided, and the wall thickness T22 of the second sidewall 12, where the second variable wall region 121 is not provided, are both 0.4 mm. This is slightly greater than that of Comparative Example 1, but still less than the minimum value of the preferred value range. In other words, the wall thickness of the first sidewall 11 and the second sidewall 12 is still insufficient. At the same time, the ratio of T2 to T1 is 0.4, slightly less than the minimum value of the preferred value range. In other words, deformation is still mainly concentrated in the first sidewall 11 and the second sidewall 12. After testing, the welding of the explosion-proof valve 2 at the third sidewall 13 of this explosion-proof housing group meets the technical requirements, and the airtightness test results also meet the technical requirements. However, the first sidewall 11 and the second sidewall 12 still show significant out-of-tolerance deformation, and the electrode group is scratched when entering the housing. The overall yield rate of the battery cell is slightly improved compared to Comparative Example 1, but still less than 95%. It can be seen that as T2 and the ratio of T2 to T1 gradually approach the minimum value of the better value range, the yield of the explosion-proof housing increases accordingly.

[0069] As shown in Table 2, the wall thickness T21 of the first side wall 11 of the explosion-proof shell of Comparative Example 3 where the first variable wall region 111 is not provided, and the wall thickness T22 of the second side wall 12 where the second variable wall region 121 is not provided, are both 0.45 mm, which is in line with the more optimal value range. However, the ratio of T2 to T1 is 0.38, which is still less than the minimum value of the more optimal value range, that is, the deformation will still be mainly concentrated on the first side wall 11 and the second side wall 12. After testing, the welding of the explosion-proof valve 2 of this set of explosion-proof shells at the third side wall 13 meets the technical requirements, and the airtightness test results also meet the technical requirements. However, the first side wall 11 and the second side wall 12 still have obvious out-of-tolerance deformation, and the pole group is scratched when entering the shell. The overall yield rate of the battery cell is slightly improved compared with Comparative Example 1, but it is still less than 96%. It can be seen that although the wall thickness of the first side wall 11 and the second side wall 12 is thick enough, when the wall thickness ratio of the first side wall 11, the second side wall 12 and the third side wall 13 does not meet the more optimal value range, the large area side wall of the shell body 1 will still be deformed.

[0070] As shown in Table 2, the wall thickness T21 of the explosion-proof housing in Comparative Example 4, where the first sidewall 11 lacks the first wall-variable region 111, and the wall thickness T22 of the second sidewall 12 lacks the second wall-variable region 121, are both 0.45 mm, falling within the optimal range. However, as T1 increases, the ratio of T2 to T1 reaches 0.3, a further decrease compared to Comparative Example 3. This indicates that deformation is still primarily concentrated in the first and second sidewalls 11 and 12. Testing shows that the welding of the explosion-proof valve 2 at the third sidewall 13 of this explosion-proof housing meets technical requirements, as does the airtightness test results. However, significant out-of-tolerance deformation occurs on the first and second sidewalls 11 and 12, leading to scratches when the electrode assembly is inserted into the housing. The overall yield rate of the battery cell is less than 94%, further decreasing compared to Comparative Example 3. This indicates that when the wall thicknesses of the first and second sidewalls 11 and 12 are sufficiently thick, the overall yield rate of the battery cell increases as the ratio of T2 to T1 approaches the optimal range.

[0071] As shown in Table 2, the wall thickness T21 of the first side wall 11 of the explosion-proof shell of Comparative Example 5 where the first variable wall area 111 is not provided, and the wall thickness T22 of the second side wall 12 where the second variable wall area 121 is not provided, are both 0.65 mm, which is in line with the optimal value range. However, the ratio of T2 to T1 is 0.65, which is greater than the maximum value of the optimal value range. After testing, the first side wall 11 and the second side wall 12 of this group of explosion-proof shells did not show any excessive deformation, and the pole group would not be scratched when entering the shell. The welding of the explosion-proof valve 2 at the third side wall 13 met the technical requirements, and the airtightness test results also met the technical requirements. The overall yield rate of the battery cell was greater than 99%. However, the cost and weight of this group of explosion-proof shells increased significantly, and due to the excessive thickness of the first side wall 11 and the second side wall 12, the battery cell capacity reduction was greater than 1%.

[0072] Table 1

[0073] category Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 T1(mm) 1 1.2 1 1.2 1 1.2 T2(mm) 0.50 0.50 0.55 0.55 0.60 0.60 W(mm) 8.00 8.00 8.00 8.00 8.00 8.00 H(mm) 5.00 5.00 5.00 5.00 5.00 5.00 T2 / T1 0.50 0.42 0.55 0.46 0.60 0.50

[0074] Table 2

[0075] category Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 T1(mm) 1 1 1.2 1.5 1 T2(mm) 0.35 0.40 0.45 0.45 0.65 W(mm) 8.00 8.00 8.00 8.00 8.00 H(mm) 5.00 5.00 5.00 5.00 5.00 T2 / T1 0.35 0.40 0.38 0.30 0.65

[0076] In order to verify the influence of the dimension W1 of the first variable wall area 111 along the width direction of the shell body 1, the dimension W2 of the second variable wall area 121 along the width direction of the shell body 1, the vertical distance H1 between the edge of the explosion-proof valve 2 close to the first side wall 11 and the first side wall 11, the vertical distance H2 between the edge of the explosion-proof valve 2 close to the second side wall 12 and the second side wall 12, and H / W on the performance of the explosion-proof shell, as shown in Tables 3 and 4 below, this embodiment provides another six groups of examples and five groups of comparative examples of explosion-proof shells, and tests them. The similarities between the six groups of examples in Table 3 and the five groups of comparative examples in Table 4 are that: the material of the explosion-proof valve 2 is MXF2, the length of the explosion-proof valve 2 is 50 mm, the width is 14 mm, the shell body 1 is extruded from three-series aluminum, the wall thickness T21 of the first side wall 11 where the first variable wall area 111 is not provided and the wall thickness T22 of the second side wall 12 where the second variable wall area 121 is not provided are the same, represented by T2, and the value of T2 is 0.5 mm, the wall thickness T1 of the third side wall 13 is 1 mm, the dimension W1 of the first variable wall area 111 along the width direction of the shell body 1 and the dimension W2 of the second variable wall area 121 along the width direction of the shell body 1 are the same, represented by W, the vertical distance H1 between the edge of the explosion-proof valve 2 close to the first side wall 11 and the first side wall 11 and the vertical distance H2 between the edge of the explosion-proof valve 2 close to the second side wall 12 and the second side wall 12 are the same, represented by H, that is, the first side wall 11 and the second side wall 12 are still arranged in mirror symmetry.

[0077] Specifically, Table 3 below shows the dimensional parameters of six groups of examples, from Examples 7 to 12, all of which meet the above-mentioned preferred ranges, for example: 0.42≤T2 / T1≤0.6, T2≥0.45mm, W≥8mm, H≥2.8mm, and 0.35≤H / W≤0.63. Testing showed that the first sidewalls 11 and second sidewalls 12 of these six groups of explosion-proof housings showed no excessive deformation, and the pole group did not scratch when entering the housing. The welding of the explosion-proof valve 2 at the third sidewall 13 met the technical requirements, and the airtightness test results also met the technical requirements. The overall yield rate of the battery cell was greater than 99%. It can be seen that when the dimensions of the explosion-proof housing meet the above-mentioned preferred ranges, the deformation problem can be completely avoided, and the blasting stability of the explosion-proof valve 2 and the airtightness of the explosion-proof housing meet the technical requirements, thereby improving the process yield rate and production efficiency of the battery cell.

[0078] As shown in Table 4, the vertical distance H1 between the edge of the explosion-proof valve 2 near the first side wall 11 and the first side wall 11, and the vertical distance H2 between the edge of the explosion-proof valve 2 near the second side wall 12 and the second side wall 12 of the explosion-proof housing of Comparative Example 6 are both 1.7 mm, which is less than the minimum value of the preferred value range. In other words, the explosion-proof valve 2 is too wide or the third side wall 13 is too narrow. Accordingly, the distance between the welding position 3 of the explosion-proof valve 2 and the large side wall of the housing body 1 is too close. The dimension W1 of the first variable wall region 111 along the width direction of the housing body 1 and the dimension W2 of the second variable wall region 121 along the width direction of the housing body 1 of the explosion-proof housing of Comparative Example 6 are both 8 mm, which is within the preferred value range. However, the ratio of H to W is 0.21, which is less than the minimum value of the preferred value range. Testing showed that the weld on the third sidewall 13 of the explosion-proof valve 2 in this explosion-proof housing met technical requirements, as did the airtightness test results. However, both the first and second sidewalls 11 and 12 exhibited significant excessive deformation, making the electrode assembly susceptible to scratches when inserted into the housing. The overall yield rate of the battery cells was less than 94%. This indicates that the weld location 3 of the explosion-proof valve 2 is too close to the large sidewall of the housing body 1, which weakens the effectiveness of the variable wall area.

[0079] As shown in Table 4, the vertical distance H1 between the edge of the explosion-proof valve 2 near the first side wall 11 and the first side wall 11, and the vertical distance H2 between the edge of the explosion-proof valve 2 near the second side wall 12 and the second side wall 12 of the explosion-proof housing of Comparative Example 7 are both 1.8 mm, which is still less than the minimum value of the preferred value range. In other words, the explosion-proof valve 2 is too wide or the third side wall 13 is too narrow. Accordingly, the distance between the welding position 3 of the explosion-proof valve 2 and the large side wall of the housing body 1 is too close. The dimension W1 of the first variable wall region 111 along the width direction of the housing body 1 and the dimension W2 of the second variable wall region 121 along the width direction of the housing body 1 of the explosion-proof housing of Comparative Example 7 are also both 8 mm, which is in line with the preferred value range. However, the ratio of H to W is 0.23, which is still less than the minimum value of the preferred value range. Testing showed that the welding of the explosion-proof valve 2 at the third side wall 13 of this explosion-proof housing met technical requirements, as did the airtightness test results. However, both the first and second side walls 11 and 12 still exhibited significant excessive deformation, making the electrode assembly susceptible to scratches when inserted into the housing. The overall yield rate of the battery cell was less than 95%, a slight increase compared to Comparative Example 6. This indicates that the closer the values of H and H / W are to the optimal range, the more the deformation problem is alleviated, and the higher the overall yield rate of the battery cell.

[0080] As shown in Table 4, the vertical distance H1 between the edge of the explosion-proof valve 2 near the first side wall 11 and the first side wall 11, and the vertical distance H2 between the edge of the explosion-proof valve 2 near the second side wall 12 and the second side wall 12, in the explosion-proof housing of Comparative Example 8, are both 2 mm, still below the minimum value of the preferred range. The dimension W1 of the first variable wall region 111 along the width of the housing body 1 and the dimension W2 of the second variable wall region 121 along the width of the housing body 1 in this explosion-proof housing set are also both 8 mm, within the preferred range. However, the ratio of H to W is 0.25, still below the minimum value of the preferred range. Testing showed that the welding of the explosion-proof valve 2 at the third side wall 13 of this explosion-proof housing set met the technical requirements, as did the airtightness test results. However, both the first and second side walls 11 and 12 still exhibited significant out-of-tolerance deformation, making the electrode assembly susceptible to scratching when inserted into the housing. The overall yield rate of the battery cells was less than 97%, a slight increase compared to Comparative Example 7. It can be seen that the closer the values of H and H / W are to the optimal value range, the more the deformation problem can be alleviated and the higher the overall yield of the battery cell.

[0081] As shown in Table 4, the dimensions W1 of the first variable wall region 111 and W2 of the second variable wall region 121 along the width of the shell body 1 in the explosion-proof housing of Comparative Example 9 are both 7.5 mm, less than the minimum value of the optimal range. However, the ratio of H to W is 0.37. The vertical distance H1 between the edge of the explosion-proof valve 2 near the first side wall 11 and the first side wall 11, and the vertical distance H2 between the edge of the explosion-proof valve 2 near the second side wall 12 and the second side wall 12, are both 2.8 mm, equal to the minimum value of the optimal range. Testing showed that the welding of the explosion-proof valve 2 at the third side wall 13 of this explosion-proof housing met the technical requirements, and the airtightness test results also met the technical requirements. However, the first and second side walls 11 and 12 still exhibited excessive deformation, making the electrode assembly easily scratched when inserted into the housing, and the overall yield rate of the battery cell was less than 97%. As can be seen, H and H / W are within the optimal range, but when W is too small, that is, when the variable wall region is too narrow, the explosion-proof housing still suffers from deformation.

[0082] As shown in Table 4, the dimensions W1 of the first variable wall region 111 and W2 of the second variable wall region 121 along the width of the shell body 1 of the explosion-proof housing of Comparative Example 10 are both 7 mm, less than the minimum value of the preferred value range. The ratio of H to W is 0.64, greater than the maximum value of the preferred value range. The vertical distance H1 between the edge of the explosion-proof valve 2 near the first side wall 11 and the first side wall 11, and the vertical distance H2 between the edge of the explosion-proof valve 2 near the second side wall 12 and the second side wall 12 are both 4.5 mm, which are within the preferred value range. After testing, the welding of the explosion-proof valve 2 at the third side wall 13 of this explosion-proof housing meets the technical requirements, and the airtightness test results also meet the technical requirements. However, the first side wall 11 and the second side wall 12 still show excessive deformation, and the electrode group is easily scratched when entering the shell. The overall yield rate of the battery cell is less than 97%. It can be seen that W is too small and H / W is too large, that is, the variable wall area is too narrow, even if the vertical distance between the explosion-proof valve 2 and the extension surface of the first side wall 11 and the second side wall 12 is large, the first side wall 11 and the second side wall 12 still have deformation problems.

[0083] Table 3

[0084]

[0085]

[0086] Table 4

[0087] category Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Comparative Example 10 T1(mm) 1 1 1 1 1 T2(mm) 0.50 0.50 0.50 0.50 0.50 W(mm) 8.00 8.00 8.00 7.50 7.00 H(mm) 1.70 1.80 2.00 2.80 4.50 H / W 0.21 0.23 0.25 0.37 0.64

[0088] It can be seen that respectively setting variable wall areas at the first side wall 11 and the second side wall 12 can effectively alleviate the deformation problem of the shell body 1 caused by welding the explosion-proof valve 2, and when the size of the explosion-proof shell meets the above-mentioned better value range, the explosion-proof shell can completely avoid the deformation problem, and the welding process difficulty of the explosion-proof valve 2 is reduced, the welding stability is improved, the blasting accuracy of the explosion-proof valve 2 and the airtightness of the explosion-proof shell meet the technical requirements, and the process yield and production efficiency of the battery cell can be improved.

[0089] This embodiment also provides a battery cell comprising a battery cell top cover, a pole group, and the aforementioned explosion-proof housing. A sealing cover is disposed at the opening of the explosion-proof housing to form the outer shell of the battery cell, and the pole group is disposed within the outer shell. This battery cell can help alleviate deformation of the housing body 1, thereby improving process yield and production efficiency.

[0090] As can be seen, the cell's top cover no longer has an explosion-proof valve 2. Instead, the valve 2 is located on the shell body 1, specifically on the third sidewall 13 of the shell body 1. This shortens the path for opening the valve to vent air in the event of thermal runaway, improving the cell's safety. The shell body 1 of this cell is extruded, requiring no additional reinforcements or process steps. Furthermore, when welding the large surfaces adjacent to the third sidewall 13 (i.e., the first and second sidewalls 11, 12) on one side of the explosion-proof valve 2, a transitional thickening design is employed. This design creates a variable wall area, which strengthens the structural strength of this area, reduces the impact of welding on the first and second sidewalls 11, 12, and increases the safety threshold for deformation resistance in the area where the explosion-proof valve 2 is located. Furthermore, the variable wall area improves the flow of the profile during extrusion molding, increasing product yield. Since the thickness of the first and second sidewalls 11, 12 is increased only near the explosion-proof valve 2, this avoids significant increases in the weight and cost of the shell body 1 and mitigates the impact on the cell's capacity. In addition, the battery cell defines the value range of each dimension through standardization, namely ensuring 0.42≤T2 / T1≤0.6, T2≥0.45mm, W≥8mm, H≥2.8mm and 0.35≤H / W≤0.63, which can further improve the deformation of the shell body 1 and even completely solve the deformation problem, significantly improving the process yield of the battery cell.

[0091] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. Explosion-proof housing, characterized in that, include: The shell body (1) comprises a first side wall (11), a third side wall (13) and a second side wall (12) connected in sequence, wherein the first side wall (11) and the second side wall (12) are arranged opposite to each other along the thickness direction of the shell body (1), the third side wall (13) is located at one end of the width direction of the shell body (1), the third side wall (13) is provided with an explosion-proof through hole (131), the wall thickness of the first side wall (11) and the wall thickness of the second side wall (12) are both smaller than that of the third side wall (13). Wall thickness, the first side wall (11) has a first variable wall region (111), the first variable wall region (111) is arranged close to the third side wall (13), and the closer the first variable wall region (111) is to the third side wall (13), the thicker the wall thickness is; the second side wall (12) has a second variable wall region (121), the second variable wall region (121) is arranged close to the third side wall (13), and the thicker the wall thickness is as the second variable wall region (121) is closer to the third side wall (13); An explosion-proof valve (2), the explosion-proof valve (2) is welded to the third side wall (13) and blocks the explosion-proof through hole (131).

2. The explosion-proof housing according to claim 1, characterized in that: The wall thickness T21 of the first side wall (11) where the first wall-changing region (111) is not provided satisfies the requirement that T21 is ≥ 0.45 mm; And / or, the wall thickness T22 of the second side wall (12) where the second wall-changing region (121) is not provided satisfies T22≥0.45 mm.

3. The explosion-proof housing according to claim 1, characterized in that: The wall thickness T21 of the first side wall (11) where the first wall-changing region (111) is not provided and the wall thickness T1 of the third side wall (13) satisfy 0.42≤T21 / T1≤0.6; And / or, the wall thickness T22 of the second side wall (12) where the second wall variable region (121) is not provided and the wall thickness T1 of the third side wall (13) satisfy 0.42≤T22 / T1≤0.

6.

4. The explosion-proof housing according to any one of claims 1 to 3, characterized in that: A dimension W1 of the first variable wall region (111) along the width direction of the shell body (1) satisfies the requirement that W1 ≥ 8 mm; The dimension W2 of the second variable wall region (121) along the width direction of the shell body (1) satisfies the requirement that W2 ≥ 8 mm.

5. The explosion-proof housing according to any one of claims 1 to 3, characterized in that: Along the width direction of the third side wall (13), a vertical distance H1 between the edge of the explosion-proof valve (2) close to the first side wall (11) and the first side wall (11) satisfies the requirement that H1 ≥ 2.8 mm; And / or, along the width direction of the third side wall (13), a vertical distance H2 between the edge of the explosion-proof valve (2) close to the second side wall (12) and the second side wall (12) satisfies: H2 ≥ 2.8 mm.

6. The explosion-proof housing according to any one of claims 1 to 3, characterized in that: The dimension of the first variable wall region (111) along the width direction of the shell body (1) is W1, and along the width direction of the third side wall (13), the vertical distance between the edge of the explosion-proof valve (2) close to the first side wall (11) and the first side wall (11) is H1, satisfying 0.35≤H1 / W1≤0.63; And / or, the dimension of the second variable wall region (121) along the width direction of the shell body (1) is W2, and along the width direction of the third side wall (13), the vertical distance between the edge of the explosion-proof valve (2) close to the second side wall (12) and the second side wall (12) is H2, satisfying 0.35≤H2 / W2≤0.

63.

7. The explosion-proof housing according to any one of claims 1 to 3, characterized in that: The first variable wall region (111) penetrates the first side wall (11) along the length direction of the shell body (1); And / or, the second variable wall region (121) passes through the second side wall (12) along the length direction of the shell body (1).

8. The explosion-proof housing according to any one of claims 1 to 3, characterized in that: The first wall-changing region (111) has a first inclined surface (1111), the first inclined surface (1111) is located at the inner wall of the shell body (1), and an obtuse angle is formed between the first inclined surface (1111) and the inner wall surface of the first side wall (11) where the first wall-changing region (111) is not provided. And / or, the second wall-changing region (121) has a second inclined surface (1211), the second inclined surface (1211) is located at the inner wall of the shell body (1), and an obtuse angle is formed between the second inclined surface (1211) and the inner wall surface of the second side wall (12) where the second wall-changing region (121) is not provided.

9. The explosion-proof housing according to any one of claims 1 to 3, characterized in that: A limiting groove (132) is provided on the outward end surface of the third side wall (13), the explosion-proof through hole (131) is provided at the bottom of the limiting groove (132), and the explosion-proof valve (2) is located in the limiting groove (132).

10. A battery cell, characterized in that: It comprises a cell top cover, a pole group and an explosion-proof shell as claimed in any one of claims 1 to 9, wherein the cell top cover sealing cover is arranged at the opening of the explosion-proof shell to form the outer shell of the cell, and the pole group is arranged in the outer shell.

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