Housing with deformation compensation

Abstract

The invention relates to the technical field of batteries, and discloses a shell with deformation compensation, the shell is expanded to form a square shell, and the shell comprises a main body with a hollow cavity and an opening; at the opening end of the main body, in two side edges, corresponding to the x direction, of the main body, at least the middle area, in the x direction, of each side edge is sunken towards the hollow cavity, so that a compensation section is formed on the side edge, and a compensation surface is formed on the side face where the side edge is located. The compensation sections are formed on the two side edges, corresponding to the x direction, of the opening end of the main body, and the compensation faces are formed on the side faces where the side edges are located, so that when the shell with deformation compensation expands outwards, the needed square shell is just formed, deformation of the shell is reduced, the assembling performance and the sealing performance of the shell and the cover plate are improved, and the service life of the shell is prolonged. The problems of poor welding of the shell and the cover plate, electrode group burning and the like are avoided, the safety performance of the assembled battery is ensured, the size precision and the appearance quality of the assembled battery are improved, and the battery can be conveniently assembled in a whole pack.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a shell with deformation compensation. Background Art

[0002] At least one end of the shell of the square battery has an opening, and the opening is provided to facilitate the insertion of the electrode group into the shell. The open end of the shell cooperates with the battery cover to form a closed space for accommodating the electrode group. The square shell is usually formed by a stretching process. Due to the open structure of the shell, the open end of the shell will expand to varying degrees after the stretching is completed. If the expansion is too much, a gap will be generated at the joint between the shell and the cover, affecting the sealing of the shell and the cover. When the shell and the cover are welded, the laser will leak into the interior of the shell, causing ablation and damage to the insulating film, diaphragm and other insulating components of the internal electrode group, affecting the safety performance of the battery. It will also cause the large surface of the battery to swell after assembly, affecting the assembly of the entire package. Summary of the Invention

[0003] In view of this, the present invention provides a shell with deformation compensation to solve the problem in the prior art that the opening end of the shell expands outward, affecting the assembly sealing of the shell and the cover, the safety of the battery, and the convenience of battery assembly.

[0004] The present invention provides a shell with deformation compensation, which forms a square shell after expansion. The square shell has x-direction, y-direction and z-direction, and includes: a main body with a hollow cavity, and at least one end of the main body along the z-direction has an opening; at the open end of the main body, the side surface where the two side edges of the main body corresponding to the x-direction are located is recessed in the direction of the hollow cavity in at least the middle area along the x-direction of each side edge, so as to form a compensation section on the side edge and a compensation surface on the side surface where the side edge is located.

[0005] In an optional embodiment, the length of the square shell along the x-direction is L; the width of the square shell along the y-direction is W; the height of the square shell along the z-direction is H; the wall thickness of the side is T; the compensation section has a theoretical compensation amount A0, which is the distance between the theoretical center position of the side along the x-direction and the center position of the corresponding long side of the square shell along the x-direction, satisfying Among them, the units of L, T, W, H, and A0 are all mm.

[0006] In an optional embodiment, the compensation section has an actual compensation amount A, which is the distance between the actual center position of the side edge along the x-direction and the center position of the corresponding long side of the square shell along the x-direction. The theoretical compensation amount A0 has a tolerance a, satisfying A=A0±a, where 0.1mm≤a≤0.3mm.

[0007] In an optional embodiment, along the x-direction, the length occupied by the compensation segment is L1, satisfying 1 / 4×L≤L1≤3 / 4×L.

[0008] In an optional embodiment, at the open end of the main body, along the y direction, the theoretical width of the shell with deformation compensation at the center position of the x direction is W0, satisfying W0=W-2×A; at the open end of the main body, along the y direction, the actual width of the shell with deformation compensation at the center position of the x direction is W1, and the theoretical width W0 has a tolerance w, satisfying W1=W0±w, where 0.01mm≤w≤0.1mm.

[0009] In an optional embodiment, the length L of the square shell satisfies 70≤L≤380 mm.

[0010] In an optional embodiment, the width W of the square shell satisfies 12≤W≤80 mm.

[0011] In an optional embodiment, the height H of the square shell satisfies 65≤H≤230 mm.

[0012] In an optional embodiment, the wall thickness T of the side meets 0.35≤T≤0.75mm.

[0013] In an optional embodiment, one end of the main body along the z direction has an opening; or, both ends of the main body along the z direction have openings.

[0014] The technical solution of this application has the following advantages:

[0015] By forming compensation sections at the two side edges corresponding to the x-direction at the open end of the main body and forming compensation surfaces on the side surfaces where the side edges are located, when the shell with deformation compensation expands outward, the required square shell is formed, the deformation of the shell is reduced, the assembly and sealing of the shell and the cover are improved, and problems such as poor welding of the shell and the cover and burning of the electrode group are avoided, thereby ensuring the safety performance of the assembled battery, improving the dimensional accuracy and appearance quality of the assembled battery, and facilitating the battery to be assembled in a whole package. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 It is a structural schematic diagram of the opening end of the shell in the related art;

[0018] Figure 2 Schematic diagram of the structure of the open end of the shell with deformation compensation according to an embodiment of the present invention;

[0019] Figure 3 for Figure 2 A schematic structural diagram of the open end of a square shell formed by expanding the shell with deformation compensation shown;

[0020] Figure 4 for Figure 3 The overall structural diagram of the square shell is shown.

[0021] Description of reference numerals:

[0022] 1. Main body; 11. Side; 111. Compensation segment; 112. Straight segment. DETAILED DESCRIPTION

[0023] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0024] The following combination Figures 2 to 4 , describing embodiments of the present invention.

[0025] According to an embodiment of the present invention, a shell with deformation compensation is provided. The shell, after expansion, forms a square shell with x-, y-, and z-directions. The shell with deformation compensation includes a main body 1 having a hollow cavity and an opening at at least one end thereof along the z-direction. At the open end of the main body 1, the side surface of the main body 1, where two side edges 11 corresponding to the x-direction are located, is recessed toward the hollow cavity in at least the middle region of each side edge 11 along the x-direction, thereby forming a compensation section 111 on the side edge 11 and a compensation surface on the side surface where the side edge 11 is located.

[0026] The shell with deformation compensation of this embodiment is applied, by forming a compensation section 111 on the two side edges 11 corresponding to the x-direction at the open end of the main body 1 and a compensation surface on the side where the side edges 11 are located. When the shell with deformation compensation expands outward, it forms the required square shell, reduces the deformation of the shell, improves the assembly and sealing of the shell and the cover, and avoids problems such as poor welding of the shell and the cover and burning of the electrode group, thereby ensuring the safety performance of the assembled battery, and improving the dimensional accuracy and appearance quality of the assembled battery, making it easier for the battery to be assembled in a whole package.

[0027] Please note that Figure 3 The open end of the square shell is a rectangular structure, that is, it includes two long sides and two short sides that are relatively spaced apart. Figure 1 At the open end of the square shell, the two large surfaces of the main body 1 corresponding to the two long sides are prone to expand outward. Therefore, the two side edges 11 mentioned above are the two long sides of the shell opening end, and the side surfaces where the two side edges 11 are located are the two large surfaces of the shell.

[0028] It is worth noting that, please refer to Figure 1 In the related art, after the square shell is directly stretched and formed by the stretching process, the two long sides at the open end of the square shell will expand outward in the direction away from the hollow cavity, causing problems such as poor assembly and welding between the shell and the cover. The battery assembled using this shell will also have problems such as short circuit and bulging. In this embodiment, please refer to Figure 2 In the area where the main body 1 is prone to outward expansion, a certain compensation amount is set in the opposite direction of the outward expansion direction. When the shell with deformation compensation shown in this embodiment is formed by the stretching process, the shell expands outward to form the required square shell (that is, the shell is formed by the stretching process). Figure 2 The shell is expanded to form Figure 3 The shell shown in the figure solves the problems of poor assembly and welding between the shell and the cover, as well as short circuit and swelling of the battery after assembly, thereby ensuring the sealing, welding quality, safety performance and assemblability of the battery.

[0029] It should be further explained that, by forming the compensation section 111 at the corresponding position of the stretching die, the shell with deformation compensation of this embodiment is formed by processing the stretching die.

[0030] In one embodiment, Figures 2 to 4 As shown, along the x-direction, the length of the square shell is L; along the y-direction, the width of the square shell is W; along the z-direction, the height of the square shell is H; the wall thickness of the side 11 is T; the compensation section 111 has a theoretical compensation amount A0, which is the distance between the theoretical center position of the side 11 along the x-direction and the center position of the corresponding long side of the square shell along the x-direction, satisfying Among them, the units of L, T, W, H, and A0 are all mm.

[0031] It's worth noting that the extent of the shell's expansion is related to its overall dimensions. The shell's length (i.e., the length of the long side of the opening) has the greatest impact on the expansion; the longer the shell, the greater the expansion. The wall thickness of the side edge 11 (i.e., the long side) of the opening also significantly affects the expansion, while the shell's width (i.e., the length of the short side of the opening) and height have less influence. Therefore, in this embodiment, the compensation amount of the compensation section 111 is limited based on the shell's overall dimensions to ensure the quality and dimensional accuracy of the square shell formed after expansion.

[0032] Please note that Figure 2 The theoretical compensation amount A0 is the distance between the center point of the long side of the opening end of the main body 1 in the x-direction and the center point of the long side of the opening end of the square shell formed after expansion in the x-direction.

[0033] In one embodiment, the compensation segment 111 has an actual compensation amount A, which is the distance between the actual center position of the side 11 along the x-direction and the center position of the corresponding long side of the rectangular housing along the x-direction. The theoretical compensation amount A0 has a tolerance a such that A=A0±a, where 0.1mm≤a≤0.3mm. For example, when a=0.2mm, the value range of A is (A0-0.2)mm≤A≤(A0+0.2)mm.

[0034] It is worth noting that during the production process, due to factors such as processing technology, there will be errors when processing the theoretical compensation amount A0. Therefore, a tolerance a is set for the theoretical compensation amount A0 so that the actual compensation amount A satisfies A=A0±a to meet actual processing requirements.

[0035] It should be noted that the center position of the side 11 along the x-direction is the intersection of the perpendicular bisector of the long side of the rectangular housing and the side 11. Furthermore, the theoretical center position of the side 11 along the x-direction is the center position obtained according to the calculation formula for A0 in this embodiment. The actual center position of the side 11 along the x-direction is the center position after A0 is given a tolerance a.

[0036] In one embodiment, Figure 2 As shown, along the x direction, the length of the compensation section 111 is L1, which satisfies 1 / 4×L≤L1≤3 / 4×L.

[0037] It is worth noting that, please refer to Figure 2The x-axis center of side edge 11 is the x-axis center of compensation segment 111. That is, on one side (left side) of this center, there is a compensation segment 111 with a length of 1 / 2 × L1, and on the other side (right side) of this center, there is a compensation segment 111 with a length of 1 / 2 × L1. Furthermore, at this center, the compensation amount of compensation segment 111 is A. The compensation amount of compensation segment 111 gradually decreases from this center toward the left and right sides.

[0038] Specifically, in this embodiment, Figure 2 As shown, side edge 11 further includes two straight segments 112. Along the x-direction, these two straight segments 112 are located on opposite sides (left and right) of compensation segment 111. One end of each straight segment 112 is connected to compensation segment 111, and the other end is connected to the short side of the open end of main body 1. Therefore, the length of each straight segment 112 is (L-L1) / 2.

[0039] It is worth noting that the middle region of the long side of the open end of the shell along the x-direction is the area with the largest degree of expansion, while the actual expansion of the two side regions outside this middle region is not zero (that is, it also has a certain degree of expansion). However, since the short side of the open end of the shell (that is, the small surface of the shell along the y-direction) provides a certain support for the two side regions, and when a compensation amount is set in the middle region, the degree of expansion of the two side regions can also be improved to a certain extent. Therefore, the expansion of the two side regions is very small. The welding assembly equipment will apply a certain suction force to the large surface of the shell when welding the shell and the cover plate, so that the welding assembly equipment has a certain degree of compatibility with the slight expansion, which will not affect the assembly of the shell and the cover plate, nor will it affect the safety performance and appearance quality of the battery. Therefore, there is no need to compensate for the two side regions of the long side of the open end of the shell along the x-direction. On the contrary, if compensation is also set for the two side regions of the long side of the open end of the shell along the x-direction, it is easy to cause the two side regions of the large surface of the shell along the x-direction to be concave, which will affect the insertion of the electrode group into the shell.

[0040] In summary, the shell with deformation compensation in this embodiment improves the problem of large-surface outward expansion of the shell while avoiding the problem of large-surface inward concavity. Therefore, it can not only ensure the coordination effect between the shell and the cover plate, but also ensure the normal insertion of the pole group into the shell, and also take into account the manufacturing window of the equipment.

[0041] It should be further explained that a suitable value for the length L1 of the compensation section 111 can be selected according to the actual size of the housing and the difference in the degree of outward expansion.

[0042] In one embodiment, Figure 2As shown, at the open end of the main body 1, along the y-direction, the theoretical width of the deformation-compensating housing at the center of the x-direction is W0, satisfying W0 = W-2×A. Along the y-direction, at the open end of the main body 1, the actual width of the deformation-compensating housing at the center of the x-direction is W1. The theoretical width W0 has a tolerance w, satisfying W1 = W0±w, where 0.01mm≤w≤0.1mm. For example, when w = 0.02mm, the value range of W1 is (W0-0.02)mm≤W1≤(W0+0.02)mm.

[0043] In one embodiment, Figure 4 As shown, the length L of the square housing satisfies 70≤L≤380 mm.

[0044] In one embodiment, Figure 4 As shown, the width W of the square housing satisfies 12≤W≤80 mm. Furthermore, the width W of the square housing has a tolerance w', so the actual width of the square housing is W±w', where 0.05 mm≤w'≤0.15 mm.

[0045] In one embodiment, Figure 4 As shown, the height H of the square housing satisfies 65≤H≤230 mm.

[0046] In one embodiment, Figure 3 As shown, the wall thickness T of the side 11 satisfies 0.35≤T≤0.75 mm.

[0047] In one embodiment, Figure 4 As shown, the main body 1 has an opening at one end along the z direction.

[0048] Of course, in other alternative embodiments, both ends of the main body 1 along the z direction may have openings.

[0049] The following describes the shell with deformation compensation in this embodiment with reference to actual cases.

[0050] In the first set of square housings for each embodiment and comparative example, L = 148 mm, W = 52 mm, H = 112 mm, and T = 0.5 mm. Calculation yields A0 = 1.582 mm, W0 = 48.836 mm, and W1 = W0 ± 0.1 = 48.836 ± 0.1. This means that the value range for W1 is 48.736 mm to 48.936 mm, and the value range for W is 51.85 mm to 52.15 mm. Table 1 illustrates the results for the housings of each embodiment and comparative example. The embodiments refer to deformation-compensating housings that meet the requirements of these embodiments, while the comparative examples refer to housings that do not meet the requirements of these embodiments.

[0051] Table 1 Results of the first group of shells of the embodiment and the comparative example

[0052]

[0053] It can be seen from Table 1 that in Examples 1 to 4, the values of W1 are all in the range of 48.736 mm to 48.936 mm. Therefore, the measured value of the width W of the square shell formed after expansion is in the range of 51.85 mm to 52.15 mm. The width of the square shell is qualified and the shell cover fits well.

[0054] It can be seen from Table 1 that in Comparative Examples 1 and 2, the value of W1 exceeds 48.936 mm, resulting in the measured value of the width W of the square shell formed after expansion exceeding 52.15 mm. The width of the square shell is too large, resulting in laser leakage during shell cover welding and ablation of the pole group insulation protective film.

[0055] It can be seen from Table 1 that in Comparative Examples 3 and 4, the value of W1 is lower than 48.736 mm, resulting in the measured value of the width W of the square shell formed after expansion being lower than 51.85 mm. The width of the square shell is too small, which makes it difficult for the cover plate to enter the shell during the shell cover welding, resulting in poor fit of the shell cover and explosion points in the welding.

[0056] In the square housings of the second set of embodiments and comparative examples, L = 70 mm, W = 20 mm, H = 65 mm, and T = 0.35 mm. Calculation yields A0 = 0.765 mm, W0 = 18.47 mm, and W1 = W0 ± 0.1 = 18.47 ± 0.1. This means that the value range of W1 is 18.37 mm to 18.57 mm, and the value range of W is 19.85 mm to 20.15 mm. Table 2 illustrates the results of the housings of the embodiments and comparative examples. The embodiments refer to housings with deformation compensation that meet the requirements of the embodiments, while the comparative examples refer to housings that do not meet the requirements of the embodiments.

[0057] Table 2 Results of the second group of shells of the embodiment and the comparative example

[0058]

[0059] It can be seen from Table 2 that in Examples 5 to 8, the values of W1 are all in the range of 18.37 mm to 18.57 mm. Therefore, the measured value of the width W of the square shell formed after expansion is in the range of 19.85 mm to 20.15 mm. The width of the square shell is qualified and the shell cover fits well.

[0060] It can be seen from Table 2 that in Comparative Examples 5 and 6, the value of W1 exceeds 18.57 mm, resulting in the measured value of the width W of the square shell formed after expansion exceeding 20.15 mm. The width of the square shell is too large, resulting in laser leakage during shell cover welding and ablation of the electrode group insulation protective film.

[0061] It can be seen from Table 2 that in Comparative Examples 7 and 8, the value of W1 is lower than 18.37 mm, resulting in the measured value of the width W of the square shell formed after expansion being lower than 19.85 mm. The width of the square shell is too small, which makes it difficult for the cover plate to enter the shell during the shell cover welding, resulting in poor fit of the shell cover and explosion points in the welding.

[0062] In the square housings of the third group of examples and comparative examples, L = 70 mm, W = 80 mm, H = 230 mm, and T = 0.75 mm. Calculation yields A0 = 3.865 mm, W0 = 72.277 mm, and W1 = W0 ± 0.1 = 72.277 ± 0.1. This means that the value range of W1 is 72.177 mm to 72.377 mm, and the value range of W is 79.85 mm to 80.15 mm. Table 3 illustrates the results of the housings of the examples and comparative examples. The examples refer to housings with deformation compensation that meet the requirements of the examples, while the comparative examples refer to housings that do not meet the requirements of the examples.

[0063] Table 3 Results of the third group of shells of the embodiment and the comparative example

[0064]

[0065] It can be seen from Table 3 that in Examples 9 to 12, the values of W1 are all in the range of 72.177 mm to 72.377 mm. Therefore, the measured value of the width W of the square shell formed after expansion is in the range of 79.85 mm to 80.15 mm. The width of the square shell is qualified and the shell cover fits well.

[0066] It can be seen from Table 3 that in Comparative Examples 9 and 10, the value of W1 exceeds 72.377 mm, resulting in the measured value of the width W of the square shell formed after expansion exceeding 80.15 mm. The width of the square shell is too large, resulting in laser leakage during shell cover welding and ablation of the electrode group insulation protective film.

[0067] It can be seen from Table 3 that in Comparative Examples 11 and 12, the value of W1 is lower than 72.177 mm, resulting in the measured value of the width W of the square shell formed after expansion being lower than 79.85 mm. The width of the square shell is too small, which makes it difficult for the cover plate to enter the shell during the shell cover welding, resulting in poor fit of the shell cover and explosion points in the welding.

[0068] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A shell with deformation compensation, which is expanded outward to form a square shell, wherein the square shell has an x-direction, a y-direction and a z-direction, and is characterized in that: include: A main body having a hollow cavity, wherein at least one end of the main body along the z direction has an opening; At the open end of the main body, the side surface where the two side edges of the main body corresponding to the x-direction are located is recessed in the direction of the hollow cavity in at least the middle area along the x-direction of each side edge to form a compensation section on the side edge and a compensation surface on the side surface where the side edge is located.

2. The housing with deformation compensation according to claim 1, characterized in that Along the x-direction, the length of the square shell is L; along the y-direction, the width of the square shell is W; along the z-direction, the height of the square shell is H; the wall thickness of the side is T; The compensation section has a theoretical compensation amount A0, which is the distance between the theoretical center position of the side along the x direction and the center position of the corresponding long side of the square shell along the x direction, satisfying Among them, the units of L, T, W, H, and A0 are all mm.

3. The housing with deformation compensation according to claim 2, characterized in that The compensation section has an actual compensation amount A, which is the distance between the actual center position of the side along the x-direction and the center position of the corresponding long side of the square shell along the x-direction. The theoretical compensation amount A0 has a tolerance a, satisfying A=A0±a, where 0.1mm≤a≤0.3mm.

4. The housing with deformation compensation according to claim 2 or 3, characterized in that: Along the x direction, the length of the compensation section is L1, which satisfies 1 / 4×L≤L1≤3 / 4×L.

5. The housing with deformation compensation according to claim 2 or 3, characterized in that: At the open end of the main body, along the y direction, the theoretical width of the center position of the shell with deformation compensation in the x direction is W0, satisfying W0=W-2×A; At the open end of the main body, along the y direction, the actual width of the shell with deformation compensation at the center position of the x direction is W1, and the theoretical width W0 has a tolerance w, satisfying W1=W0±w, where 0.01mm≤w≤0.1mm.

6. The housing with deformation compensation according to claim 2 or 3, characterized in that: The length L of the square shell satisfies 70≤L≤380mm.

7. The housing with deformation compensation according to claim 2 or 3, characterized in that: The width W of the square housing satisfies 12≤W≤80 mm.

8. The housing with deformation compensation according to claim 2 or 3, characterized in that: The height H of the square shell satisfies 65≤H≤230 mm.

9. The housing with deformation compensation according to claim 2 or 3, characterized in that: The wall thickness T of the side meets 0.35≤T≤0.75mm.

10. The housing with deformation compensation according to any one of claims 1 to 3, characterized in that One end of the main body along the x-direction has an opening; or both ends of the main body along the x-direction have openings.

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