Battery case and battery cell

Abstract

The invention belongs to the technical field of batteries, and discloses a battery shell and a battery single.The battery shell comprises a first wall body and two second wall bodies, an anti-explosion hole is formed in the first wall body, the two second wall bodies are connected with the two opposite sides of the first wall body respectively, the second wall bodies are provided with protruding parts, and the protruding parts are connected to the first wall body in the circumferential direction of the anti-explosion hole; according to the structure, the structural strength of the area, close to the anti-explosion hole, of the second wall body can be improved, the probability of deformation of the second wall body can be reduced when the anti-explosion hole is punched in the first wall body and the anti-explosion valve is welded to the anti-explosion hole, the effect of improving the welding yield of the anti-explosion valve is achieved, and the welding quality of the anti-explosion valve is improved. And a powerful guarantee is provided for smoothly loading the pole group into the battery shell.

Description

Technical Field

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

[0002] Currently, common steel-shell batteries include rectangular batteries and cylindrical batteries. Among them, an explosion-proof valve is provided on the small surface of the steel shell of the rectangular battery. When the internal air pressure of the steel shell reaches the bursting value, the explosion-proof valve opens to discharge the high-pressure gas inside the steel shell.

[0003] When assembling the explosion-proof valve and the steel shell, it is necessary to first punch an explosion-proof hole on the small surface of the steel shell, and then weld the explosion-proof valve at the explosion-proof hole. Since the wall thickness of the steel shell is generally thin, the structural strength of the steel shell is low. When punching the explosion-proof hole, the large surface of the steel shell adjacent to the small surface of the steel shell is likely to deform, thereby deforming the explosion-proof hole, reducing the welding yield rate of the explosion-proof valve, and the deformation of the large surface of the steel shell is not conducive to the smooth loading of the electrode group into the steel shell. In addition, a large amount of heat is generated during the welding of the explosion-proof valve, making the large surface of the steel shell with a thin wall thickness prone to plastic deformation. If the welding heat cannot be quickly dissipated, the deformation amount of the large surface of the steel shell will increase. The plastic deformation of the large surface of the steel shell will also cause the explosion-proof hole to deform, thereby reducing the welding yield rate of the explosion-proof valve, making the explosion-proof valve unable to be sealed and plugged at the explosion-proof hole.

[0004] Therefore, it is urgent to propose a battery case and a battery cell to solve the above technical problems. Summary of the Invention

[0005] The first object of the present invention is to provide a battery case in which the probability of deformation of the second wall body is relatively low when punching the explosion-proof hole on the first wall body and when welding the explosion-proof valve at the explosion-proof hole.

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

[0007] A battery case, comprising:

[0008] A first wall body, on which an explosion-proof hole is provided;

[0009] Two second wall bodies, which are respectively connected to the two opposite sides of the first wall body. The second wall body is provided with a protruding portion, and the protruding portion is connected to the first wall body around the circumference of the explosion-proof hole.

[0010] Optionally, the wall thickness of the first wall body is H1, and the sum of the wall thickness of the second wall body and the thickness of the protruding portion protruding from the second wall body is H3, and H1 / H3 ≤ 1.85.

[0011] Optionally, H1 / H3 > 1.

[0012] Optionally, H3 ≥ 0.65 mm.

[0013] Optionally, two second wall bodies are oppositely arranged in the first direction, the number of the first wall bodies is two, the two first wall bodies are oppositely arranged in the third direction, the first direction and the third direction are perpendicular, and both ends of the protruding portion are respectively connected to the first wall bodies on the circumference of an explosion-proof hole.

[0014] Optionally, the protruding portion extends in the third direction.

[0015] Optionally, the dimension of the protruding portion in the second direction is W, the aperture of the explosion-proof hole in the second direction is L, W / L≥0.62, and both the first direction and the third direction are perpendicular to the second direction.

[0016] Optionally, the first wall body is the wall body with the largest thickness of the battery case.

[0017] Optionally, a protruding portion is provided on one side of one of the two second wall bodies facing the other.

[0018] The second object of the present invention is to provide a battery cell, which has a high welding yield of the explosion-proof valve, and a high yield and efficiency of assembling the electrode group into the battery case.

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

[0020] The battery cell includes an electrode group and the above-mentioned battery case, and the electrode group is arranged in the battery case.

[0021] The beneficial effects of the present invention:

[0022] For the battery case provided by the present invention, an explosion-proof hole is provided on the first wall body, a protruding portion is provided on the second wall body, and the protruding portion is connected to the first wall body on the circumference of the explosion-proof hole. That is to say, at least part of the protruding portion is located in the area of the second wall body close to the explosion-proof hole (hereinafter referred to as the corresponding area), and the protruding portion is connected to the first wall body on the circumference of the explosion-proof hole, playing a certain supporting role. It can be seen that this structural design increases the structural strength of the second wall body in the corresponding area. Therefore, when stamping the explosion-proof hole on the first wall body, the probability of the second wall body deforming can be reduced. When welding the explosion-proof valve at the explosion-proof hole, the probability of the second wall body undergoing plastic deformation is also relatively low, which has the effect of improving the welding yield of the explosion-proof valve, and also provides a strong guarantee for the smooth installation of the electrode group into the battery case. Description of the Drawings

[0023] Figure 1 is an exploded structural schematic diagram of the battery case provided by the present invention;

[0024] Figure 2 is a perspective view of the battery case (without showing the explosion-proof valve) provided by the present invention;

[0025] Figure 3 is a structural schematic diagram of the battery case provided by the present invention;

[0026] Figure 4 is Figure 3 Cross-sectional view in the E-E direction in;

[0027] Figure 5 is Figure 4 Partial enlarged view at location A in;

[0028] Figure 6 is Figure 4 Cross-sectional view in the F-F direction in;

[0029] Figure 7 is Figure 6 Partial enlarged view at location B in;

[0030] Figure 8 It is a schematic structural diagram of a battery cell provided by the present invention.

[0031] In the figure:

[0032] D1, the first direction; D2, the second direction; D3, the third direction;

[0033] 10, battery case; 20, cover plate;

[0034] 100, the first wall body; 110, explosion-proof hole; 200, the second wall body; 210, protruding part; 220, slope; 300, explosion-proof valve; 400, opening. Specific embodiments

[0035] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. Additionally, it should be noted that for the sake of description, only parts related to the present invention rather than all structures are shown in the drawings.

[0036] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected", and "fixed" shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] In the present invention, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may include direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the horizontal height of the first feature is less than that of the second feature.

[0038] In the description of this embodiment, the orientation or positional relationships such as "upper", "lower", "right", etc. are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0039] This embodiment provides a battery case. When stamping an explosion-proof hole on the first wall body and welding an explosion-proof valve at the explosion-proof hole, the probability of deformation of the second wall body is relatively low.

[0040] Specifically, as Figure 1 and Figure 2 shown, the battery case 10 includes a first wall body 100 and two second wall bodies 200. Among them, an explosion-proof hole 110 is provided on the first wall body 100, and an explosion-proof valve 300 is hermetically welded at the explosion-proof hole 110. The two second wall bodies 200 are respectively connected to the two opposite sides of the first wall body 100. The second wall body 200 is provided with a protruding portion 210, and the protruding portion 210 is connected to the first wall body 100 in the circumferential direction of the explosion-proof hole 110.

[0041] Based on the above design, an explosion-proof hole 110 is provided on the first wall body 100, a protruding portion 210 is provided on the second wall body 200, and the protruding portion 210 is connected to the first wall body 100 in the circumferential direction of the explosion-proof hole 110. That is to say, at least part of the protruding portion 210 is located in the area of the second wall body 200 close to the explosion-proof hole 110 (hereinafter referred to as the corresponding area), and the protruding portion 210 is connected to the first wall body 100 in the circumferential direction of the explosion-proof hole 110, playing a certain supporting role. It can be seen that this structural design increases the structural strength of the second wall body 200 in the corresponding area. Furthermore, when stamping the explosion-proof hole 110 on the first wall body 100, the probability of deformation of the second wall body 200 can be reduced. When welding the explosion-proof valve 300 at the explosion-proof hole 110, the probability of plastic deformation of the second wall body 200 is also relatively low, which has the effect of improving the welding yield of the explosion-proof valve 300, and also provides a strong guarantee for the smooth loading of the electrode group into the battery case 10.

[0042] Moreover, compared with increasing the overall wall thickness of the second wall body 200, in this embodiment, the convex portions 210 are only added in partial areas of the second wall body 200, that is, the wall thickness is only increased in local areas of the second wall body 200. This structural design not only reduces the material consumption of the second wall body 200, achieving the effect of reducing production costs; but also on the basis of improving the structural strength of the corresponding areas of the second wall body 200, reduces the weight of the battery case 10 and improves the utilization rate of the internal space of the battery case 10, which is beneficial to improving the energy density of the battery cell.

[0043] It should be noted that the above stamping process and welding process are both relatively mature production processes in the art. Making the explosion-proof holes 110 on the first wall body 100 by the stamping process and welding the explosion-proof valve 300 at the explosion-proof holes 110 by the welding process is conducive to realizing the automated batch production of the battery cell.

[0044] Optionally, the two second wall bodies 200 are arranged oppositely in the first direction D1, the number of the first wall bodies 100 is two, the two first wall bodies 100 are arranged oppositely in the third direction D3, the first direction D1 and the third direction D3 are perpendicular, and both ends of the convex portion 210 are respectively connected to the first wall body 100 on the circumference of an explosion-proof hole 110. That is to say, the battery case 10 provided in this embodiment is of a square structure. Of course, in other implementation schemes, the battery case 10 can also be other structures such as a pentagonal prism. And, there are two explosion-proof holes 110 provided on the battery case 10 provided in this embodiment. When the internal pressure of the battery case 10 reaches the bursting value, the high-pressure gas in the battery case 10 can be discharged from the explosion-proof valves 300 at the two explosion-proof holes 110 respectively, which not only shortens the gas flow path, but also increases the gas discharge outlet, greatly improving the gas discharge efficiency and having the effect of improving the use safety of the battery cell. In addition, both ends of the convex portion 210 are respectively connected to the first wall body 100 on the circumference of an explosion-proof hole 110, thereby being able to support the areas of the second wall body 200 close to the two explosion-proof holes 110 and improving the structural strength, and can simultaneously reduce the probability of deformation problems occurring in the two corresponding areas on the second wall body 200.

[0045] Furthermore, as Figure 2 and Figure 4 shown, the convex portion 210 extends along the third direction D3. On the one hand, it makes the structure of the convex portion 210 have better consistency. On the other hand, it makes the convex portion 210 concentrated in the area of the second wall body 200 corresponding to the explosion-proof hole 110, which can further improve the structural strength of the corresponding area of the second wall body 200, and further reduce the probability of deformation problems occurring in the corresponding area.

[0046] Optionally, as Figure 1As shown, a convex portion 210 is provided on one side of one of the two second wall bodies 200 facing the other, so as to ensure that the surfaces on the sides of the two second wall bodies 200 facing away from each other are flat, improving the overall structural consistency of the battery case 10; moreover, the structure in which the two convex portions 210 are oppositely arranged in the first direction D1 can achieve a good limiting effect on the electrode group, that is, after the electrode group is inserted into the battery case 10, the electrode group can be clamped between the two convex portions 210, achieving the effect of restricting the movement of the electrode group in the first direction D1. Moreover, after the electrode group is inserted into the battery case 10, the convex portion 210 forms a gap between the side wall of the electrode group and the inner wall of the second wall body 200, and this gap expands the flow space of the gas in the battery case 10. When the air pressure in the battery case 10 reaches the bursting value, it is beneficial for the gas in the battery case 10 to be quickly discharged. Of course, in other embodiments, it may also be that convex portions 210 are provided on the sides of the two second wall bodies 200 facing away from each other, or convex portions 210 may be provided on both the sides of the two second wall bodies 200 facing away from each other and the sides of the two second wall bodies 200 facing each other.

[0047] Optionally, as Figures 5 to 7 shown, the wall thickness of the first wall body 100 is H1, and the sum of the wall thickness of the second wall body 200 and the thickness by which the convex portion 210 protrudes from the second wall body 200 is H3, and H1 / H3≤1.85. Exemplarily, H1 / H3 can be 1.85, 1.6 or 1.3, etc., ensuring that the area of the second wall body 200 provided with the convex portion 210 has sufficient thickness, providing a strong guarantee for the structural strength of the corresponding area of the second wall body 200.

[0048] Furthermore, the first wall body 100 is the wall body with the largest thickness of the battery case 10. When stamping the explosion-proof hole 110 on the first wall body 100, this design can reduce the probability of deformation at the edge of the explosion-proof hole 110, and thus can improve the welding yield of the explosion-proof valve 300. The battery case 10 provided in this embodiment has two first wall bodies 100 and two second wall bodies 200. Regarding the wall thickness of the second wall body 200 as H2, then H1>H2.

[0049] Furthermore, H1 / H3>1. Exemplarily, H1 / H3 can be 1.1, 1.2 or 1.5, etc. This design can, on the one hand, ensure that the first wall body 100 has a relatively large thickness, and when stamping the explosion-proof hole 110 on the first wall body 100, reduce the probability of deformation at the edge of the explosion-proof hole 110. On the other hand, since H1>H2, if H1 / H3<1, then H1<H3, that is to say, the size by which the convex portion 210 protrudes from the surface of the second wall body 200 is relatively large, which will reduce the internal space utilization rate of the battery case 10, increase the weight of the battery case 10 and increase the material cost, and is not conducive to improving the energy density of the battery cell and reducing the production cost.

[0050] Optionally, H3≥0.65mm. Exemplarily, H3 can be 0.65mm, 0.7mm, 0.75mm, etc., to ensure that the corresponding area of the second wall 200 has sufficient structural strength, that is, to ensure that the corresponding area has sufficient anti-deformation ability.

[0051] Optionally, H1≥1mm. Exemplarily, H1 can be 1mm, 1.5mm, 2mm, etc., to ensure that the first wall 100 has a sufficient wall thickness and structural strength, and to avoid the problem of deformation of the first wall 100 when stamping the explosion-proof hole 110 on the first wall 100.

[0052] Optionally, 0.3mm≤H2≤0.8mm. Exemplarily, H2 can be 0.3mm, 0.5mm, 0.8mm, etc., so that the second wall 200 has a certain structural strength, and it is only necessary to ensure that the first wall 100 is the wall with the largest wall thickness of the battery case 10 (i.e., H1>H2).

[0053] Optionally, as Figures 3 to 7 shown, the dimension of the protruding portion 210 in the second direction D2 is W, and the aperture of the explosion-proof hole 110 in the second direction D2 is L, and W / L≥0.62. The first direction D1 and the third direction D3 are both perpendicular to the second direction D2. Exemplarily, W / L can be 0.62, 0.7, 0.8, etc., to ensure that the volume of the protruding portion 210 in the second direction D2 is relatively large, thereby providing a strong guarantee for the structural strength of the corresponding area on the second wall 200.

[0054] It should be noted that in this embodiment, the explosion-proof hole 110 is a stepped hole. When welding the explosion-proof valve 300, first place the explosion-proof valve 300 on the stepped plane of the stepped hole, and then weld the edge of the stepped hole and the edge of the explosion-proof valve 300. Therefore, the above L is the maximum aperture of the stepped hole in the second direction D2, and L is also the dimension of the explosion-proof valve 300 in the second direction D2.

[0055] Optionally, as Figure 7 shown, the edge of the protruding portion 210 in the second direction D2 is a slope surface 220. When assembling the electrode group into the battery case 10, the slope surface 220 can reduce the probability of the electrode group being scratched, and has the effect of protecting the electrode group. Secondly, as Figure 1 shown, the battery case 10 in this embodiment is a square structure, and openings 400 are provided at both ends of the battery case 10 in the second direction D2. When assembling the electrode group into the battery case 10, the electrode group is gradually assembled into the battery case 10 from the openings 400 along the second direction D2. During this process, the slope surface 220 can play a certain guiding role for the electrode group, improving the efficiency and accuracy of the electrode group entering the case. Thirdly, if the protruding portion 210 is formed by a stamping process, the design of the slope surface 220 is beneficial to stamping forming, and has the effects of reducing the production difficulty and improving the production efficiency.

[0056]

[0057] Table 1 provides six groups of examples and five groups of comparative examples. The material of the battery case 10 in the six groups of examples and the five groups of comparative examples is MXF2. The length (i.e., L) of the explosion-proof valve 300 is 65 mm, the width of the explosion-proof valve 300 is 15 mm, and the laser welding power when welding the explosion-proof valve 300 at the explosion-proof hole 110 is 1000 W.

[0058] In Example 1, the wall thickness H1 of the first wall 100 is 1 mm, the wall thickness H2 of the second wall 200 is 0.5 mm, the sum H3 of the wall thickness of the second wall 200 and the thickness by which the protrusion 210 protrudes from the second wall 200 is 0.65 mm, the dimension W of the protrusion 210 in the second direction D2 is 48 mm, the aperture diameter L of the explosion-proof hole 110 in the second direction D2 is 65 mm, H1 / H3 is 1.54, W / L is 0.74. After stamping the explosion-proof hole 110 on the first wall 100 and welding the explosion-proof valve 300 at the explosion-proof hole 110, no excessive concave occurs in the corresponding area of the second wall 200, and both the welding helium inspection (i.e., the sealing test of the welding part) and the appearance of the battery case 10 meet the technical requirements.

[0059] In Example 2, the wall thickness H1 of the first wall 100 is 1 mm, the wall thickness H2 of the second wall 200 is 0.55 mm, the sum H3 of the wall thickness of the second wall 200 and the thickness by which the protrusion 210 protrudes from the second wall 200 is 0.7 mm, the dimension W of the protrusion 210 in the second direction D2 is 48 mm, the aperture diameter L of the explosion-proof hole 110 in the second direction D2 is 65 mm, H1 / H3 is 1.43, W / L is 0.74. After stamping the explosion-proof hole 110 on the first wall 100 and welding the explosion-proof valve 300 at the explosion-proof hole 110, no excessive concave occurs in the corresponding area of the second wall 200, and both the welding helium inspection (i.e., the sealing test of the welding part) and the appearance of the battery case 10 meet the technical requirements.

[0060] In Example 3, the wall thickness H1 of the first wall 100 is 1.2 mm, the wall thickness H2 of the second wall 200 is 0.5 mm, the sum H3 of the wall thickness of the second wall 200 and the thickness by which the protrusion 210 protrudes from the second wall 200 is 0.65 mm, the dimension W of the protrusion 210 in the second direction D2 is 48 mm, the aperture diameter L of the explosion-proof hole 110 in the second direction D2 is 65 mm, H1 / H3 is 1.85, W / L is 0.74. After stamping the explosion-proof hole 110 on the first wall 100 and welding the explosion-proof valve 300 at the explosion-proof hole 110, no excessive concave occurs in the corresponding area of the second wall 200, and both the welding helium inspection (i.e., the sealing test of the welding part) and the appearance of the battery case 10 meet the technical requirements.

[0061] In Example 4, the wall thickness H1 of the first wall body 100 is 1.2 mm, the wall thickness H2 of the second wall body 200 is 0.5 mm, the sum H3 of the wall thickness of the second wall body 200 and the thickness by which the protrusion 210 protrudes from the second wall body 200 is 0.7 mm, the dimension W of the protrusion 210 in the second direction D2 is 48 mm, the aperture diameter L of the explosion-proof hole 110 in the second direction D2 is 65 mm, H1 / H3 is 1.71, and W / L is 0.74. After stamping the explosion-proof hole 110 on the first wall body 100 and welding the explosion-proof valve 300 at the explosion-proof hole 110, no out-of-tolerance concave occurs in the corresponding area of the second wall body 200, and both the helium leak detection for welding (i.e., the sealing test at the welding point) and the appearance of the battery case 10 meet the technical requirements.

[0062] In Example 5, the wall thickness H1 of the first wall body 100 is 1.2 mm, the wall thickness H2 of the second wall body 200 is 0.5 mm, the sum H3 of the wall thickness of the second wall body 200 and the thickness by which the protrusion 210 protrudes from the second wall body 200 is 0.75 mm, the dimension W of the protrusion 210 in the second direction D2 is 45 mm, the aperture diameter L of the explosion-proof hole 110 in the second direction D2 is 65 mm, H1 / H3 is 1.6, and W / L is 0.69. After stamping the explosion-proof hole 110 on the first wall body 100 and welding the explosion-proof valve 300 at the explosion-proof hole 110, no out-of-tolerance concave occurs in the corresponding area of the second wall body 200, and both the helium leak detection for welding (i.e., the sealing test at the welding point) and the appearance of the battery case 10 meet the technical requirements.

[0063] In Example 6, the wall thickness H1 of the first wall body 100 is 1.2 mm, the wall thickness H2 of the second wall body 200 is 0.5 mm, the sum H3 of the wall thickness of the second wall body 200 and the thickness by which the protrusion 210 protrudes from the second wall body 200 is 0.8 mm, the dimension W of the protrusion 210 in the second direction D2 is 40 mm, the aperture diameter L of the explosion-proof hole 110 in the second direction D2 is 65 mm, H1 / H3 is 1.5, and W / L is 0.62. After stamping the explosion-proof hole 110 on the first wall body 100 and welding the explosion-proof valve 300 at the explosion-proof hole 110, no out-of-tolerance concave occurs in the corresponding area of the second wall body 200, and both the helium leak detection for welding (i.e., the sealing test at the welding point) and the appearance of the battery case 10 meet the technical requirements.

[0064] In Comparative Example 1, the wall thickness H1 of the first wall 100 is 1.2 mm, the wall thickness H2 of the second wall 200 is 0.5 mm, the sum H3 of the wall thickness of the second wall 200 and the thickness by which the protrusion 210 protrudes from the second wall 200 is 0.65 mm, the dimension W of the protrusion 210 in the second direction D2 is 35 mm, the aperture diameter L of the explosion-proof hole 110 in the second direction D2 is 65 mm, H1 / H3 is 1.85, and W / L is 0.54. After stamping the explosion-proof hole 110 on the first wall 100 and welding the explosion-proof valve 300 at the explosion-proof hole 110, the concave amplitude of the corresponding area of the second wall 200 is greater than 0.3 mm, that is, the corresponding area of the second wall 200 has an out-of-tolerance concave, and the welding yield is less than 98%, not meeting the technical requirements.

[0065] In Comparative Example 2, the wall thickness H1 of the first wall 100 is 1.2 mm, the wall thickness H2 of the second wall 200 is 0.5 mm, the sum H3 of the wall thickness of the second wall 200 and the thickness by which the protrusion 210 protrudes from the second wall 200 is 0.6 mm, the dimension W of the protrusion 210 in the second direction D2 is 48 mm, the aperture diameter L of the explosion-proof hole 110 in the second direction D2 is 65 mm, H1 / H3 is 2, and W / L is 0.74. After stamping the explosion-proof hole 110 on the first wall 100 and welding the explosion-proof valve 300 at the explosion-proof hole 110, the concave amplitude of the corresponding area of the second wall 200 is greater than 0.3 mm, that is, the corresponding area of the second wall 200 has an out-of-tolerance concave, and the welding yield is less than 98%, not meeting the technical requirements.

[0066] In Comparative Example 3, the wall thickness H1 of the first wall 100 is 1.2 mm, the wall thickness H2 of the second wall 200 is 0.5 mm, the sum H3 of the wall thickness of the second wall 200 and the thickness by which the protrusion 210 protrudes from the second wall 200 is 0.55 mm, the dimension W of the protrusion 210 in the second direction D2 is 48 mm, the aperture diameter L of the explosion-proof hole 110 in the second direction D2 is 65 mm, H1 / H3 is 2.18, and W / L is 0.74. After stamping the explosion-proof hole 110 on the first wall 100 and welding the explosion-proof valve 300 at the explosion-proof hole 110, the concave amplitude of the corresponding area of the second wall 200 is greater than 0.3 mm, that is, the corresponding area of the second wall 200 has an out-of-tolerance concave, and the welding yield is less than 98%, not meeting the technical requirements.

[0067] In Comparative Example 4, the wall thickness H1 of the first wall body 100 is 1.2 mm, the wall thickness H2 of the second wall body 200 is 0.5 mm, the sum H3 of the wall thickness of the second wall body 200 and the thickness by which the protruding portion 210 protrudes from the second wall body 200 is 0.5 mm, the dimension W of the protruding portion 210 in the second direction D2 is 48 mm, the aperture diameter L of the explosion-proof hole 110 in the second direction D2 is 65 mm, H1 / H3 is 2.4, and W / L is 0.74. After stamping the explosion-proof hole 110 on the first wall body 100 and welding the explosion-proof valve 300 at the explosion-proof hole 110, the concave amplitude of the corresponding area of the second wall body 200 is greater than 0.3 mm, that is, the corresponding area of the second wall body 200 has an out-of-tolerance concave, and the welding yield is less than 98%, not meeting the technical requirements.

[0068] In Comparative Example 5, the wall thickness H1 of the first wall body 100 is 1.2 mm, the wall thickness H2 of the second wall body 200 is 0.5 mm, the sum H3 of the wall thickness of the second wall body 200 and the thickness by which the protruding portion 210 protrudes from the second wall body 200 is 0.7 mm, the dimension W of the protruding portion 210 in the second direction D2 is 38 mm, the aperture diameter L of the explosion-proof hole 110 in the second direction D2 is 65 mm, H1 / H3 is 1.71, and W / L is 0.58. After stamping the explosion-proof hole 110 on the first wall body 100 and welding the explosion-proof valve 300 at the explosion-proof hole 110, the concave amplitude of the corresponding area of the second wall body 200 is greater than 0.3 mm, that is, the corresponding area of the second wall body 200 has an out-of-tolerance concave, and the welding yield is less than 98%, not meeting the technical requirements.

[0069] In summary, when 1 < H1 / H3 ≤ 1.85, W / L ≥ 0.62, H1 ≥ 1 mm, and H3 ≥ 0.65 mm, after stamping the explosion-proof hole 110 on the first wall body 100 and welding the explosion-proof valve 300 at the explosion-proof hole 110, the corresponding area of the second wall body 200 will not have an out-of-tolerance concave, and both the welding helium leak detection (i.e., the sealing test of the welding joint) and the appearance of the battery case 10 can meet the technical requirements.

[0070] This embodiment also provides a battery cell, as Figure 1 and Figure 8 shown. The battery cell includes a cover plate 20, a pole group (not shown in the figure), and the above-mentioned battery case 10. An opening 400 is provided at the end of the battery case 10 in the second direction D2, the cover plate 20 seals the opening 400, and the pole group is arranged inside the battery case 10. This battery cell uses the above-mentioned battery case 10. When stamping the explosion-proof hole 110 on the first wall body 100 and welding the explosion-proof valve 300 at the explosion-proof hole 110, the probability of deformation of the second wall body 200 is small. Therefore, the welding yield of welding the explosion-proof valve 300 at the explosion-proof hole 110 is high, and the pole group can be smoothly installed into the battery case 10, which can not only reduce the probability of the problem of rubbing between the pole group and the second wall body 200, but also improve the efficiency of installing the pole group into the case.

[0071] Compared with the case where the explosion-proof valve 300 is disposed on the cover plate 20, in this embodiment, the explosion-proof valve 300 is disposed on the first wall body 100, which can shorten the flow path of the gas in the battery case 10. When the air pressure in the battery case 10 reaches the bursting value, the gas in the battery case 10 can be quickly discharged from the battery case 10, greatly improving the use safety of the battery cell.

[0072] Obviously, the above embodiments of the present invention are merely examples for clearly explaining the present invention, rather than limiting the embodiments of the present invention. For those of ordinary skill in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to enumerate all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A battery case, characterized in that: include: A first wall body (100), wherein the first wall body (100) is provided with an explosion-proof hole (110); Two second wall bodies (200), the two second wall bodies (200) are respectively connected to two opposite sides of the first wall body (100), the second wall body (200) is provided with a protrusion (210), and the protrusion (210) is connected to the first wall body (100) in the circumferential direction of the explosion-proof hole (110).

2. The battery case according to claim 1, characterized in that: The wall thickness of the first wall (100) is H1, the sum of the wall thickness of the second wall (200) and the thickness of the protruding portion (210) protruding from the second wall (200) is H3, and H1 / H3≤1.

85.

3. The battery case according to claim 2, characterized in that: H1 / H3>1.

4. The battery case according to claim 2, characterized in that: H3≥0.65mm.

5. The battery case according to any one of claims 1 to 4, characterized in that: The two second walls (200) are arranged opposite to each other in a first direction (D1), the number of the first walls (100) is two, the two first walls (100) are arranged opposite to each other in a third direction (D3), the first direction (D1) and the third direction (D3) are perpendicular, and the two ends of the protrusion (210) are respectively connected to one of the first walls (100) in the circumferential direction of the explosion-proof hole (110).

6. The battery case according to claim 5, characterized in that: The protruding portion (210) extends along the third direction (D3).

7. The battery case according to claim 6, characterized in that: The size of the protrusion (210) in the second direction (D2) is W, the aperture of the explosion-proof hole (110) in the second direction (D2) is L, W / L≥0.62, and the first direction (D1) and the third direction (D3) are both perpendicular to the second direction (D2).

8. The battery case according to any one of claims 1 to 4, characterized in that: The first wall (100) is the wall of the battery shell (10) with the largest thickness.

9. The battery case according to any one of claims 1 to 4, characterized in that: The protruding portion (210) is provided on a side of one of the two second walls (200) facing the other.

10. A battery cell, characterized in that: It comprises a pole group and a battery shell (10) according to any one of claims 1 to 9, wherein the pole group is arranged in the battery shell (10).

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