Battery

Abstract

The utility model provides a battery which comprises a battery shell and a battery cell located in the battery shell, the battery shell comprises a first pressure relief structure, the first pressure relief structure comprises a pressure relief groove, the concave direction of the pressure relief groove faces the direction of the battery cell, the pressure relief groove protrudes out of the inner surface of the battery shell, the bottom wall of the pressure relief groove is provided with a first thinning area, and the first thinning area is provided with a second thinning area. The thickness of the first thinning area is smaller than the wall thickness of the battery shell; when the pressure in the battery is relatively large, the wall thickness of the first thinning area is relatively thin, and gas in the battery shell can preferentially break through the first thinning area, so that pressure relief and explosion prevention are realized; besides, by means of the side walls of the pressure relief grooves, transmission of force in the direction parallel to the anti-explosion face of the battery shell to the first thinning area after the battery falls off is reduced, then the probability that the first thinning area cracks in the falling process can be reduced, meanwhile, the dependent variable of the first pressure relief structure in the thickness direction in the blasting process is increased, and the blasting quality of the battery is improved. Therefore, a buffering effect is achieved, and the explosion-proof effect of the battery is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of battery manufacturing, in particular to a battery. Background Art

[0002] To ensure the safety of lithium batteries, most lithium batteries are equipped with thin-walled areas on the packaging shell to achieve the effect of pressure relief and explosion prevention under high pressure. However, due to the influence of process consistency and material consistency, the pressure relief threshold of the above thin-walled area is difficult to control, and it is usually too sensitive or does not meet the safety level. Specifically, when the pressure relief area of ​​the steel shell battery is too thin, the pressure relief area is easily pulled during the drop test, thereby cracking and releasing pressure; if the pressure relief area of ​​the steel shell battery is too thick, although it can be guaranteed that the pressure relief area will not crack and release pressure in advance during the drop process, but during the high temperature test, the gas in the shell is difficult to break through the thin wall of the pressure relief area, making it difficult to achieve timely explosion. Utility Model Content

[0003] In view of this, the utility model is dedicated to providing a battery, by improving the structure of the thin-walled area of ​​the battery shell, so that the pressure relief area of ​​the battery shell can be exploded in time and will not crack prematurely due to falling.

[0004] In order to achieve the above object, the utility model provides the following technical solutions:

[0005] A battery comprises a battery shell and a battery cell located in the battery shell, wherein the battery shell comprises a first pressure relief structure, the first pressure relief structure comprises a pressure relief groove, the depression direction of the pressure relief groove is toward the battery cell, and the pressure relief groove protrudes from the inner surface of the battery shell, the bottom wall of the pressure relief groove has a first thinning area, and the thickness of the first thinning area is less than the wall thickness of the battery shell.

[0006] Preferably, the depth of the pressure relief groove is a, the wall thickness of the battery housing is b, and 10%*b<a<200%*b; and / or

[0007] The angle between the side wall of the pressure relief groove and the bottom wall of the pressure relief groove is r, and r≥90°; and / or

[0008] The thinning depth of the first thinning zone is c, and c≥60%*b; and / or

[0009] The area of ​​the bottom surface of the pressure relief groove occupied by the first thinning zone is m, the area of ​​the bottom surface of the pressure relief groove is n, and m / n≥0.5.

[0010] Preferably, the first pressure relief structure is distributed on the first surface of the battery housing and close to the first side wall of the battery housing, the distance between the center of the first pressure relief structure and the first side wall is g, and 0.1mm≤g≤3mm; and / or

[0011] The first pressure relief structure is distributed on the second surface of the battery housing, the depth of the pressure relief groove is a, and a≤3mm.

[0012] Preferably, the battery housing has a second pressure relief structure disposed adjacent to the first pressure relief structure on one side of the battery housing having the first pressure relief structure;

[0013] The second pressure relief structure is a second thinning area, and the thinning depth of the first thinning area is greater than the thinning depth of the second thinning area.

[0014] Preferably, a plurality of the second pressure relief structures are provided, and the plurality of the second pressure relief structures are arranged around the first pressure relief structure.

[0015] Preferably, a plurality of the second thinned areas extend in a direction away from the center of the pressure relief groove.

[0016] Preferably, the extension direction of the part of the first thinning zone close to the end is consistent with that of the second thinning zone.

[0017] Preferably, the area of ​​the bottom surface of the pressure relief groove occupied by the first thinned area is m, the area of ​​the surface of the battery housing occupied by the second thinned area is p, and m / p≥0.5.

[0018] Preferably, the distance between the second thinning area and the first thinning area is e, the distance between the first thinning area and the side wall of the pressure relief groove is f, and e>f.

[0019] Preferably, there is hot melt adhesive between the battery housing and the battery core;

[0020] In the wall thickness direction of the battery housing, the projections of the first pressure relief structure and the second pressure relief structure do not overlap with the projection of the hot melt adhesive.

[0021] It can be seen from the above technical solutions that when the internal pressure of the battery shell in the utility model is relatively large, due to the thin wall thickness of the first thinning area, the gas inside the battery shell will first break through the first thinning area, thereby achieving pressure relief and explosion prevention. In addition, by setting the first thinning area for preventing battery explosion on the bottom wall of the pressure relief groove, and limiting the depression direction of the pressure relief groove to the direction toward the battery cell, and the pressure relief groove protruding from the inner surface of the battery shell, the side wall of the pressure relief groove is used to reduce the transmission of the force in the direction parallel to the explosion-proof surface of the battery shell to the first thinning area after the battery falls, thereby reducing the probability of the first thinning area rupturing during the fall. At the same time, it increases the strain of the first pressure relief structure in the thickness direction during the explosion process to play a buffering role and improve the explosion-proof effect of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Shown is an exploded view of a battery provided in an embodiment of the utility model;

[0023] Figure 2 Shown Figure 1 A partial enlarged view of the middle A area;

[0024] Figure 3 Shown Figure 1 A distribution diagram of a first pressure relief structure and a second pressure relief structure of a battery;

[0025] Figure 4 Shown Figure 3 Section along BB direction;

[0026] Figure 5 Shown Figure 4 A partial enlarged view of the middle C area;

[0027] Figure 6 Shown is another distribution diagram of the first pressure relief structure and the second pressure relief structure in the embodiment of the utility model;

[0028] Figure 7 Shown is another distribution diagram of the first pressure relief structure and the second pressure relief structure in the embodiment of the utility model;

[0029] Figure 8 Shown is another distribution diagram of the first pressure relief structure and the second pressure relief structure in an embodiment of the present utility model.

[0030] exist Figure 1-Figure 8 middle:

[0031] 1-battery housing, 2-first pressure relief structure, 3-battery core, 4-second pressure relief structure;

[0032] 11-cover body, 12-bottom shell;

[0033] 21-pressure relief groove, 22-first thinning zone. DETAILED DESCRIPTION

[0034] An embodiment of the utility model provides a battery.

[0035] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0036] like Figure 1-Figure 4 As shown, the battery in the embodiment of the utility model includes a battery housing 1 and a battery cell 3 arranged inside the battery housing 1, wherein the battery housing 1 includes a cover body 11 and a bottom shell 12, and a first pressure relief structure 2 is arranged on the cover body 11 and / or the bottom shell 12, and the first pressure relief structure 2 includes a pressure relief groove 21, and the pressure relief groove 21 is formed on the cover plate and / or the bottom shell 12 of the battery housing 1 by stamping. The concave direction of the pressure relief groove 21 is toward the direction of the battery cell 3, and the pressure relief groove 21 protrudes from the inner surface of the battery housing 1, and the bottom wall of the pressure relief groove 21 has The first thinning area 22 is provided, and the thickness of the first thinning area 22 is less than the wall thickness of the battery shell 1; in this way, when the pressure inside the battery increases due to high temperature, due to the thin wall thickness of the first thinning area 22, the gas inside the battery shell 1 will first break through the first thinning area 22, thereby achieving pressure relief and explosion prevention. In addition, since the pressure relief groove 21 protrudes from the inner surface of the battery shell 1, the side wall of the pressure relief groove 21 can play the role of pre-storing materials, thereby increasing the strain of the first pressure relief structure 2 in the thickness direction during the pressure relief process, so as to play a buffering role and improve At the same time, the side wall of the pressure relief groove 21 can also play the role of isolating stress, avoiding the stress generated by falling to be transferred to the first thinning area 22, and reducing the probability of the first thinning area 22 being broken during the battery falling process. Specifically, since the first thinning area 22 is arranged on the bottom wall of the pressure relief groove 21, and the concave direction of the pressure relief groove 21 is toward the direction of the battery core 3, when the battery accidentally falls, under the protection of the pressure relief groove 21, the first thinning area 22 will not contact the falling surface (the falling surface is the battery after falling). , the surface that receives the battery, such as the ground or a desktop), therefore, when the battery falls, the first pressure relief structure 2 is mainly subjected to the force parallel to the explosion-proof surface of the battery casing 1 (that is, the surface of the battery casing 1 on which the first pressure relief structure 2 is arranged), and since the structural strength of the side wall of the pressure relief groove 21 is higher than the plane of the battery casing 1, during the falling process, it can withstand the force parallel to the explosion-proof surface of the battery casing 1, reducing the transmission of the above-mentioned force to the first thinning area 22, thereby reducing the probability of rupture of the first thinning area 22 during the falling process.

[0037] It should be noted that the present invention does not specifically limit the method for forming the first thinning zone 22. In some preferred embodiments, the bottom wall of the pressure relief groove 21 is processed by material removal to form the first thinning zone 22. For example, the first thinning zone 22 can be formed by laser ablation, etching, machining and the like.

[0038] Further, in some preferred embodiments, Figure 5 As shown, the depth of the pressure relief groove 21 is a, the wall thickness of the battery housing 1 is b, and 10%*b<a<200%*b. This arrangement can, on the one hand, prevent the pressure relief groove 21 from being too deep, resulting in the wall thickness of the pressure relief groove 21 being too thin after processing, affecting the strength of the pressure relief groove 21; on the other hand, it can ensure that the first pressure relief structure 2 has sufficient pre-stocked materials, thereby improving the explosion-proof effect of the first pressure relief structure 2.

[0039] In addition, as described above, the side wall of the pressure relief groove 21 has the function of pre-storing materials. On this basis, in order to improve the buffering effect of the side wall of the pressure relief groove 21, in some embodiments, the angle between the side wall of the pressure relief groove 21 and the bottom wall of the pressure relief groove 21 is r, and r>90°. In this way, the ability of the side wall of the pressure relief groove 21 to resist the force in the direction perpendicular to the explosion-proof surface (i.e., the surface of the battery housing 1 provided with the first pressure relief structure 2) can be reduced to improve the buffering effect of the side wall of the pressure relief groove 21. At the same time, the above angle range is also convenient for the stamping forming of the pressure relief groove 21. As for the specific value of the angle r, in the implementation process, it can be adaptively designed as needed. In some exemplary embodiments, the angle between the side wall of the pressure relief groove 21 and the bottom wall of the pressure relief groove 21 is 100°; in other exemplary embodiments, the angle between the side wall of the pressure relief groove 21 and the bottom wall of the pressure relief groove 21 is 110°.

[0040] Of course, when there is no need to consider the influence of the angle between the side wall of the pressure relief groove 21 and the bottom wall of the pressure relief groove 21 on the energy absorption effect of the side wall of the pressure relief groove 21, the angle between the side wall of the pressure relief groove 21 and the bottom wall of the pressure relief groove 21 can also be set to 90°.

[0041] In addition, it should be noted that the first thinning area 22 can occupy the entire bottom wall of the pressure relief groove 21, or only occupy a partial area of ​​the bottom wall, and the adaptive design is carried out according to specific needs. In some preferred embodiments, the first thinning area 22 occupies a partial area of ​​the bottom wall, the thinning depth of the first thinning area 22 is c, and c ≥ 60% * b; the area of ​​the bottom surface of the pressure relief groove 21 occupied by the first thinning area 22 is m, the area of ​​the bottom surface of the pressure relief groove 21 is n, and m / n ≥ 0.5. In this way, it is ensured that when the pressure inside the battery shell 1 increases due to high temperature, the first thinning area 22 on the battery shell 1 can be broken first, and can be broken in time to avoid the battery from exploding due to the pressure accumulation inside the battery shell 1.

[0042] The first pressure relief structure 2 can be distributed on the first surface of the battery housing 1 (i.e., the surface of the battery housing that is parallel to both the length direction and the width direction), or on the second surface of the battery housing 1 (i.e., the surface of the battery housing that is parallel to the thickness direction), or two first pressure relief structures 2 are provided, and the two first pressure relief structures 2 are distributed on the first surface and the second surface, respectively. The utility model does not limit the specific distribution of the first pressure relief structure 2, but no matter which surface the first pressure relief structure 2 is distributed on, it should be ensured that there is no interference between the first pressure relief structure 2 and the battery cell 3 inside the battery housing 1. Based on this, in some embodiments, the first pressure relief structure 2 is distributed on the first surface of the battery housing 1, and is arranged close to the first side wall of the battery housing 1, and the distance between the center of the first pressure relief structure 2 and the first side wall is g, and 0.1mm≤g≤3mm. In other embodiments, the first pressure relief structure 2 is distributed on the second surface of the battery housing 1, and the depth of the pressure relief groove 21 is a, and a≤3mm.

[0043] In addition, if Figure 1-Figure 8 As shown, in some preferred embodiments, the battery housing 1 also has a second pressure relief structure 4, which is arranged on the explosion-proof surface of the battery housing 1 (i.e., the surface of the battery housing 1 on which the first pressure relief structure 2 is arranged), and is arranged adjacent to the first pressure relief structure 2. The second pressure relief structure 4 is a second thinning area, and the thinning depth of the second thinning area is d, and c>d. In this way, the second thinning area will not rupture due to the thick wall thickness when the battery falls, and when the pressure inside the battery housing 1 increases due to high temperature, the first thinning area 22 will rupture first, and after the first thinning area 22 ruptures, since the first thinning area 22 is adjacent to the second thinning area, it will trigger the rupture of the first thinning area 22, thereby achieving the effect of expanding the pressure relief area and improving the explosion-proof effect of the battery, and at the same time, it will not affect the battery's ability to resist falling.

[0044] The number of second pressure relief structures 4 can be adaptively designed as needed, for example, one, two or three can be provided. In some preferred embodiments, multiple second pressure relief structures 4 are provided, and multiple second pressure relief structures 4 are arranged around the first pressure relief structure 2. When the internal pressure of the battery housing 1 increases, the first pressure relief structure 2 and multiple second pressure relief structures 4 are successively ruptured, thereby improving the explosion-proof effect of the battery.

[0045] In addition, regarding the shapes and distribution of the first pressure relief structure 2 and the second pressure relief structure 4, in specific implementation, they can be adaptively designed according to the needs of the battery, for example:

[0046] In some embodiments, the second pressure relief structure is a second thinning area, and multiple second thinning areas are provided, and multiple second thinning areas extend in a direction away from the center of the pressure relief groove; specifically, in some embodiments, the opening end surface of the pressure relief groove 21 is triangular, the first thinning area 22 is cross-shaped and located in the central area of ​​the pressure relief groove 21, the second thinning area is long strip-shaped, and multiple second thinning areas extend in a direction away from the center of the pressure relief groove 21. Further, as Figure 7 As shown, three second thinning areas are provided, and the three second thinning areas are respectively located at three corners of the pressure relief groove 21. In other embodiments, the opening end surface of the pressure relief groove 21 is circular, the first thinning area 22 is cross-shaped and located in the central area of ​​the pressure relief groove 21, the second thinning area is long strip-shaped, and the plurality of second thinning areas extend in a direction away from the center of the pressure relief groove 21. Further, as Figure 8 As shown, four second thinning areas are provided, and the four second thinning areas are evenly distributed around the pressure relief groove 21 .

[0047] In other embodiments, the local part of the first thinning area near the end is consistent with the extension direction of the second thinning area. Specifically, in some embodiments, the first thinning area 22 and the second thinning area are both long strips, and the extension direction of the second thinning area is consistent with the extension direction of the first thinning area 22. In this way, the second thinning area is more likely to rupture under the initiation of the first thinning area 22. For example, Figure 3 As shown, the open end face of the pressure relief groove 21 is rectangular, the first thinning area 22 is a straight strip, and the first thinning area 22 extends along the length direction of the rectangle, two second thinning areas are provided, and are distributed at both ends of the first thinning area 22 along the length direction, the second thinning area is also a straight strip, and the extension direction of the second thinning area is consistent with the extension direction of the first thinning area 22. In other embodiments, the open end face of the pressure relief groove 21 is L-shaped, the first thinning area 22 is L-shaped, the second thinning area is a strip, and multiple second thinning areas are distributed on the extension line of the end of the first thinning area 22, and the extension direction of the second thinning area is consistent with the extension direction of the extension line. Further, as Figure 6As shown, two second thinning regions are provided, and the two second thinning regions are respectively located on the extension lines of the two ends of the first thinning region 22 .

[0048] Further, in some preferred embodiments, the area of ​​the bottom surface of the pressure relief groove 21 occupied by the first thinning area 22 is m, the area of ​​the surface of the battery housing 1 occupied by the second thinning area is p, and m / p ≥ 0.5. In this way, after the first thinning area 22 is broken, the second thinning area can be broken in time under the initiation of the first thinning area 22 to ensure the explosion-proof performance of the battery.

[0049] Further, such as Figure 5 As shown, the distance between the second thinning area and the first thinning area 22 is e, the distance between the first thinning area 22 and the side wall of the pressure relief groove 21 is f, and e>f. That is, the first pressure relief structure 2 and the second pressure relief structure 4 are adjacent to each other, but there is no intersection area between them, so as to avoid the second pressure relief structure 4 affecting the strength of the side wall of the pressure relief groove 21, causing the first thinning area 22 to crack when the battery falls.

[0050] Furthermore, in some embodiments, there is hot melt adhesive between the battery housing 1 and the battery cell 3 for fixing the battery cell 3, and the battery housing 1 has a first pressure relief structure 2 and a second pressure relief structure 4. In the wall thickness direction of the battery housing 1, the projection of the first pressure relief structure 2 and the second pressure relief structure 4 and the projection of the hot melt adhesive do not overlap, so as to avoid the hot melt adhesive affecting the rupture of the first pressure relief structure 2 and the second pressure relief structure 4 in the battery housing 1, thereby ensuring the explosion-proof performance of the battery housing 1.

[0051] The basic principle of the present invention is described above in conjunction with specific embodiments. However, it should be pointed out that the advantages, strengths, effects, etc. mentioned in the present invention are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. must be possessed by each embodiment of the present invention. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not limitation, and the above details do not limit the present invention to be implemented by adopting the above specific details.

[0052] It should also be noted that in the device, apparatus and method of the present invention, each component or each step can be decomposed and / or reassembled, and such decomposition and / or reassembly shall be regarded as an equivalent solution of the present invention.

[0053] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present invention. Therefore, the present invention is not intended to be limited to the aspects shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0054] It should be understood that the limiting terms "first", "second", "third", "fourth", "fifth" and "sixth" used in the description of the embodiments of the present invention are only used to more clearly explain the technical solutions and cannot be used to limit the scope of protection of the present invention.

[0055] The above description has been given for the purpose of illustration and description. In addition, this description is not intended to limit the embodiments of the utility model to the forms disclosed herein. Although multiple example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, changes, additions and sub-combinations thereof.

Claims

1. A battery, comprising a battery housing (1) and a battery cell (3) located in the battery housing (1), characterized in that: The battery housing (1) comprises a first pressure relief structure (2), the first pressure relief structure (2) comprising a pressure relief groove (21), the depression direction of the pressure relief groove (21) is towards the battery cell (3), and the pressure relief groove (21) protrudes from the inner surface of the battery housing (1), the bottom wall of the pressure relief groove (21) has a first thinning area (22), and the thickness of the first thinning area (22) is less than the wall thickness of the battery housing (1).

2. The battery according to claim 1, characterized in that The depth of the pressure relief groove (21) is a, the wall thickness of the battery housing (1) is b, and 10%*b<a<200%*b; and / or The angle between the side wall of the pressure relief groove (21) and the bottom wall of the pressure relief groove (21) is r, and r≥90°; and / or The thinning depth of the first thinning zone (22) is c, and c≥60%*b; and / or The area of ​​the bottom surface of the pressure relief groove (21) occupied by the first thinned region (22) is m, the area of ​​the bottom surface of the pressure relief groove (21) is n, and m / n≥0.

5.

3. The battery according to claim 1, characterized in that The first pressure relief structure (2) is distributed on the first surface of the battery housing (1) and is close to the first side wall of the battery housing (1), the distance between the center of the first pressure relief structure (2) and the first side wall is g, and 0.1 mm ≤ g ≤ 3 mm; and / or The first pressure relief structure (2) is distributed on the second surface of the battery housing (1), and the depth of the pressure relief groove (21) is a, and a≤3 mm.

4. The battery according to claim 1, characterized in that The battery housing (1) further comprises a second pressure relief structure (4) disposed adjacent to the first pressure relief structure (2) on the side thereof having the first pressure relief structure (2); The second pressure relief structure (4) is a second thinning zone, and the thinning depth of the first thinning zone (22) is greater than the thinning depth of the second thinning zone.

5. The battery according to claim 4, characterized in that A plurality of the second pressure relief structures (4) are provided, and the plurality of the second pressure relief structures (4) are arranged around the first pressure relief structure (2).

6. The battery according to claim 5, characterized in that A plurality of the second thinned areas extend in a direction away from the center of the pressure relief groove (21).

7. The battery according to claim 4, characterized in that The extension direction of a part of the first thinned area (22) close to the end is consistent with that of the second thinned area.

8. The battery according to claim 4, characterized in that The area of ​​the bottom surface of the pressure relief groove (21) occupied by the first thinned area (22) is m, the area of ​​the surface of the battery housing (1) occupied by the second thinned area is p, and m / p≥0.

5.

9. The battery according to claim 4, characterized in that The distance between the second thinning area and the first thinning area (22) is e, the distance between the first thinning area (22) and the side wall of the pressure relief groove (21) is f, and e>f.

10. The battery according to claim 4, characterized in that There is hot melt adhesive between the battery housing (1) and the battery core (3); In the wall thickness direction of the battery housing (1), the projections of the first pressure relief structure (2) and the second pressure relief structure (4) do not overlap with the projection of the hot melt adhesive.

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