Cover plate assembly and battery

Abstract

The invention provides a cover plate assembly and a battery, the cover plate assembly comprises a cover plate body, a first insulating part and a first connecting piece, and the cover plate body is provided with an anti-explosion valve and a first pole; the first insulating part is arranged on the inner side of the cover plate body; the first connecting sheet is positioned on one side, far away from the cover plate body, of the first insulating part and is electrically connected with the first pole; the first connecting sheet comprises a first part and a second part, and the first part is connected with the first pole; the second part is connected with the first part and located below the anti-explosion valve, a first gap is reserved between the second part and the anti-explosion valve, and the second part is provided with a first through hole. Therefore, the first connecting piece in the cover plate assembly supports the pole group, so that the pole group is prevented from moving or deforming to block the anti-explosion valve during thermal runaway; through the first gap and the first through hole, an exhaust channel is formed between the first connecting piece and the anti-explosion valve, and the situation that exhaust cannot be achieved when the anti-explosion valve is blocked is avoided.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a cover plate assembly and a battery. Background Technology

[0002] With the rapid development of electronic products, batteries are being used more and more widely. As an important component of batteries, the battery cover has the most complex structure. When the battery experiences thermal runaway, the temperature becomes too high, and the lower plastic will completely melt at high temperatures, thus losing its supporting and limiting function for the electrode assembly. When the high-temperature and high-pressure gas inside the battery is rapidly discharged through the explosion-proof valve, the electrode assembly will be pushed up by the airflow and stick to the cover, which may block the explosion-proof valve. This could lead to the high-temperature and high-pressure gas inside the battery not being able to be discharged in time, accelerating thermal runaway, and even causing an explosion, which poses a significant risk.

[0003] Therefore, how to ensure battery safety when the plastic melts is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, this application provides a cover assembly that can address the problem of gas inside the battery not being able to escape in a timely manner when the plastic melts.

[0005] To achieve the above objectives, this application provides the following technical solution:

[0006] A cover plate assembly, comprising:

[0007] The cover plate body is equipped with an explosion-proof valve and a first pole column;

[0008] The first insulating element is disposed on the inner side of the cover plate body;

[0009] The first connecting piece is located on the side of the first insulating member away from the cover plate body and is electrically connected to the first pole post;

[0010] The first connecting piece includes:

[0011] The first part, at least a portion of which is electrically connected to the first pole post;

[0012] The second part is electrically connected to the first part in at least a portion of its area. The second part is located below the explosion-proof valve and has a first gap between it and the explosion-proof valve. The second part is provided with a first through hole.

[0013] Optionally, in the above-mentioned cover plate assembly, the first connecting piece has a support platform protruding from its side near the first insulating member.

[0014] Optionally, in the above-mentioned cover plate assembly, the projection of the support platform on the cover plate body is located between the explosion-proof valve and the first pole post, and is relatively close to the explosion-proof valve;

[0015] And / or, on both sides of the length centerline of the cover plate assembly, a plurality of support platforms are symmetrically arranged on the side of the first connecting piece.

[0016] Optionally, in the above-mentioned cover plate assembly, the area of ​​the first region enclosed by the groove of the explosion-proof valve within its plane is S1;

[0017] In the thickness direction of the cover plate body, the area of ​​the first through hole of the first connecting piece in the first region is S4;

[0018] In the thickness direction of the cover plate body, the projected area of ​​the first connecting piece in the first region is S5, 0.3≤S4 / S5≤0.9.

[0019] Optionally, in the above-described cover plate assembly,

[0020] In the thickness direction of the cover plate body, the difference between the area S1 of the first region and the projected area S5 of the first connecting piece in the first region is S2.

[0021] In the thickness direction of the cover plate body, the sum of the air passage areas formed on the first gap by the outer contour lines of the second part that overlap with the projection of the groove of the explosion-proof valve is S3, 0.8≤(S2+S3+S4) / S1≤5.

[0022] Optionally, in the above-described cover plate assembly, in the thickness direction of the cover plate body, the thickness dimension of the first gap is greater than or equal to the protrusion height of the support platform relative to the first side surface, where the first side surface is the side of the first connecting piece close to the cover plate body.

[0023] Optionally, in the above-described cover plate assembly, the second part is provided with a plurality of first through holes arranged side by side along the length direction of the cover plate body;

[0024] And / or, in the width direction of the cover plate body, the second part is provided with a plurality of the first through holes arranged side by side.

[0025] Optionally, in the above-described cover assembly, a second through hole is provided in the area of ​​the explosion-proof valve covered by the first insulating member.

[0026] Optionally, in the above-mentioned cover plate assembly, the cover plate body is further provided with a second pole post, and a second electrical connection piece electrically connected to the second pole post;

[0027] Along the length of the cover plate body:

[0028] The second pole and the first pole are located on both sides of the explosion-proof valve, respectively;

[0029] The gap between the first connecting piece and the second connecting piece is greater than or equal to 10 mm.

[0030] Optionally, in the above-mentioned cover plate assembly, along the length direction of the cover plate body, the distance between the first through hole near the explosion-proof valve and the first through hole near the first pole post is A;

[0031] Along the length of the cover plate body, the dimension between the projection of the free end of the second part onto the cover plate body and the side of the explosion-proof valve near the first pole post is C, where 4mm≤C≤1.2×A.

[0032] Optionally, in the above-described cover plate assembly, the width of the cover plate assembly is B along the width direction of the cover plate body;

[0033] Along the width direction of the cover plate body, the distance between the edge of the first connecting piece and the edge of the cover plate body adjacent to it is D, 2.5mm≤D≤1 / 3×B.

[0034] A battery includes a battery casing, an electrode assembly, and a cover assembly, the cover assembly being used to cover an opening in the battery casing, the electrode assembly being located within the battery casing, and the cover assembly being the aforementioned cover assembly.

[0035] In the cover plate assembly provided in this application, the second part of the connecting piece is located at the position of the explosion-proof valve on the cover plate body, and the first insulating member is located between the cover plate body and the connecting piece. The connecting piece supports the electrode assembly and prevents the electrode assembly from moving or deforming and blocking the explosion-proof valve during thermal runaway. The first gap and the first through hole form an exhaust channel between the connecting piece and the explosion-proof valve to prevent the explosion-proof valve from being blocked and unable to exhaust. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0037] Figure 1 An exploded view of the cover plate assembly provided in the embodiments of this application;

[0038] Figure 2 This is a schematic diagram of the structure of the connecting piece provided in the embodiments of this application;

[0039] Figure 3 A bottom view of the cover plate assembly provided in an embodiment of this application;

[0040] Figure 4 for Figure 3 AA section view in the middle;

[0041] Figure 5 This is a schematic diagram of the structure of the cover plate assembly provided in an embodiment of this application;

[0042] Figure 6 A schematic diagram of the scoring and connecting piece structure of the explosion-proof valve provided in the embodiments of this application. Figure 1 ;

[0043] Figure 7 This is a schematic diagram of the structure of the channel within the groove range of the explosion-proof valve provided in the embodiments of this application;

[0044] Figure 8 for Figure 7 CC cross-section view in the middle;

[0045] Figure 9 for Figure 7 DD cross-section view in the middle;

[0046] Figure 10 A schematic diagram of the scoring and connecting piece structure of the explosion-proof valve provided in the embodiments of this application. Figure 2 .

[0047] in:

[0048] 1. Cover plate body; 11. Explosion-proof valve; 12. First pole; 13. Second pole; 14. Second connecting piece;

[0049] 2. First insulating component; 21. Second through hole;

[0050] 3. First connecting piece; 31. First part; 311. Support platform; 32. Second part; 321. First through hole;

[0051] 4. Second insulating component; 5. Sealing component; 6. Protective component. Detailed Implementation

[0052] This application provides a cover plate assembly.

[0053] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0054] like Figures 1-10 As shown, this application provides a cover assembly that can solve the problem of gas inside the battery not being able to escape in time when the lower plastic melts.

[0055] First, the cover plate assembly includes a cover plate body 1, a first insulating member 2, and a first connecting piece 3. The cover plate body 1 is provided with an explosion-proof valve 11 and a first pole post 12. The first insulating member 2 is disposed on the inner side of the cover plate body 1. The first connecting piece 3 is located on the side of the first insulating member 2 away from the cover plate body 1 and is electrically connected to the first pole post 12. The first connecting piece 3 includes a first part 31 and a second part 32. At least a portion of the first part 31 is electrically connected to the first pole post 12. At least a portion of the second part 32 is electrically connected to the first part 31. The second part 32 is located below the explosion-proof valve 11 and has a first gap with the explosion-proof valve 11. The second part 32 is provided with a first through hole 321. This can be understood as follows: the second part 32 is located directly below the explosion-proof valve 11, and the first part 31 is all parts of the first connecting piece 3 except for the second part 32; or the first connecting piece 3 includes the first part 31 and the second part 32 connected in sequence along the length direction of the cover plate body 1, and when the end of the first connecting piece 3 near the second part 32 is flush with the edge of the explosion-proof valve 11 along the length direction of the cover plate body 1, the second part 32 is located directly below the explosion-proof valve 11, and the first part 31 is all parts of the first connecting piece 3 except for the second part 32; or, when the first connecting piece 3 includes the first part 31 and the second part 32 connected in sequence along the length direction of the cover plate body 1, and when the end of the first connecting piece 3 near the second part 32 extends beyond the edge of the explosion-proof valve 11 along the length direction of the cover plate body 1, the second part 32 includes the part located directly below the explosion-proof valve 11 and the end extending beyond the edge of the explosion-proof valve 11, and the first part 31 is all parts of the first connecting piece 3 except for the second part 32.

[0056] As can be seen, in the cover plate assembly provided in this application embodiment, the second part 32 of the first connecting piece 3 is disposed at the position of the explosion-proof valve 11 of the cover plate body 1, and the first insulating member 2 is located between the cover plate body 1 and the first connecting piece 3. The first connecting piece 3 supports the electrode group and prevents the electrode group from moving or deforming and blocking the explosion-proof valve 11 during thermal runaway. The first gap and the first through hole 321 form an exhaust channel between the first connecting piece 3 and the explosion-proof valve 11 to prevent the explosion-proof valve 11 from being unable to exhaust when it is blocked.

[0057] In some embodiments, a support platform 311 protrudes from the side of the first connecting piece 3 near the first insulating member 2. The support platform 311 can improve the strength and rigidity of the first connecting piece 3, and at the same time, it can serve as a support for the pole assembly. It should be noted that the first part 31 at the position of the support platform 311 is flush with the side of the first insulating member 2; or the first part 31 at the position of the support platform 311 is recessed to form a recessed area.

[0058] In some embodiments, the projection of the support platform 311 onto the cover plate body 1 is located between the explosion-proof valve 11 and the first pole post 12, and relatively close to the explosion-proof valve 11. This not only prevents interference with the connection to the first pole post 12, but also provides support for the second part 32, preventing it from tilting; and / or, multiple support platforms 311 are symmetrically arranged on the sides of the first connecting piece 3 on both sides of the length centerline of the cover plate assembly, which can improve the stability of the support, such as... Figure 2 As shown, on both sides of the center line of the length of the cover plate assembly, two support platforms 311 are symmetrically arranged on the side of the first part 31.

[0059] In some embodiments, the area of ​​the first region enclosed by the grooves of the explosion-proof valve 11 in its plane is S1; the area of ​​the first through hole 321 of the first connecting piece 3 in the first region in the thickness direction of the cover plate body 1 is S4; the projected area of ​​the first connecting piece 3 in the first region in the thickness direction of the cover plate body 1 is S5, where 0.3 ≤ S4 / S5 ≤ 0.9. It should be noted that S4 / S5 can be any one of 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, and 0.9.

[0060] Table 1 below shows the test results for the specific values ​​of S4 / S5 when the battery experiences thermal runaway:

[0061] Table 1

[0062]

[0063]

[0064] As can be seen from Table 1, controlling the size of S4 / S5 can prevent it from being too small, which would result in a small air passage area on the first connecting piece 3. In the event of thermal runaway, the hole would be blocked, which would not be conducive to the normal opening of the explosion-proof valve 11 for exhaust, reduce the exhaust heat dissipation speed, and cause the battery thermal runaway experiment to fail. It can also prevent it from being too large, which would result in a reduction in the protection area of ​​the explosion-proof valve 11 and damage to the explosion-proof valve 11.

[0065] In some embodiments, in the thickness direction of the cover plate body 1, the difference between the area S1 of the first region and the projected area S5 of the first connecting piece 3 in the first region is S2; in the thickness direction of the cover plate body 1, the sum of the air passage areas formed by the outer contour lines of the second part 32 and the etched projection of the explosion-proof valve 11 on the first gap is S3, and 0.8≤(S2+S3+S4) / S1≤5. It should be noted that (S2+S3+S4) / S1 can be any one of the following: 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.

[0066] Table 2 shows the test results for the specific values ​​of (S2+S3+S4) / S1 when the battery experiences thermal runaway.

[0067] Table 2

[0068]

[0069] As can be seen from Table 2, controlling the value of (S2+S3+S4) / S1 can prevent it from being too small, which would result in a small total exhaust channel area and failure of the thermal runaway experiment; it can also prevent it from being too large, which would affect the width of the first connecting piece 3.

[0070] In some embodiments, in the thickness direction of the cover plate body 1, the thickness of the first gap is greater than or equal to the protrusion height of the support platform 311 relative to the first side surface, where the first side surface is the side of the first connecting piece 3 near the cover plate body 1. That is, the thickness of the first gap is greater than the protrusion height of the support platform 311 relative to the first side surface; or the thickness of the first gap is equal to the protrusion height of the support platform 311 relative to the first side surface. This provides height space for the support platform 311 while also allowing an exhaust channel to be formed between the first connecting piece 3 and the explosion-proof valve 11 through the first gap.

[0071] In some embodiments, a plurality of first through holes 321 are arranged side-by-side in the second part 32 along the length direction of the cover body 1; and / or, a plurality of first through holes 321 are arranged side-by-side in the width direction of the cover body 1. It should be noted that the length direction of the cover body 1 is the length direction of the battery, and the width direction of the cover body 1 is the thickness direction of the battery. The arrangement of multiple first through holes 321 allows for better communication with the first gap, forming an exhaust channel between the first connecting piece 3 and the explosion-proof valve 11. Even when some of the first through holes 321 are blocked by the melted first insulating member 2, other first through holes 321 can still ensure the formation of an exhaust channel.

[0072] In some embodiments, a second through hole 21 is provided in the area of ​​the first insulating member 2 covering the explosion-proof valve 11. The second through hole 21 communicates with the first through hole 321, enabling an exhaust channel to be formed between the first connecting piece 3 and the explosion-proof valve 11.

[0073] In some embodiments, the cover plate body 1 is further provided with a second pole post 13 and a second electrical connecting piece electrically connected to the second pole post 13; along the length direction of the cover plate body 1: the second pole post 13 and the first pole post 12 are respectively located on both sides of the explosion-proof valve 11; the gap between the first connecting piece 3 and the second connecting piece 14 is greater than or equal to 10mm. This can avoid the situation where the first connecting piece 3 and the second connecting piece 14 are short-circuited due to the distance being too small, and at the same time, it can avoid the situation where the injection port is blocked and affects the injection effect, and it can also avoid the situation where there is interference with the injection port.

[0074] In some embodiments, along the length of the cover plate body 1, the distance between the first through hole 321 near the explosion-proof valve 11 and the first through hole 321 near the first pole post 12 is A. It should be noted that when the explosion-proof valve 11 has one first through hole 321, or when multiple first through holes 321 are arranged in a straight line along the width of the cover plate body 1, A is the diameter of the first through hole 321. When there are multiple first through holes 321 and they are not arranged in a straight line along the width of the cover plate body 1, A is the dimension between the holes of the two first through holes 321 on the two edges of the cover plate body 1 that are away from each other. Along the length of the cover plate body 1, the dimension between the free end of the second part 32 and the side of the explosion-proof valve 11 near the first pole post 12 is C, where 4mm≤C≤1.2×A.

[0075] Table 3 below shows the test results for the specific values ​​of C and A when the battery experiences thermal runaway:

[0076] Table 3

[0077]

[0078] As can be seen from Table 3, controlling the values ​​of C and A can prevent the first connecting piece 3 from being too small, resulting in a poor blocking effect due to its distance from the explosion-proof valve 11; it can also prevent the first connecting piece 3 from being too large, resulting in it blocking the injection port or being too close to another first connecting piece 3.

[0079] In some embodiments, the width of the cover assembly is B along the width direction of the cover body 1; the distance between the first connecting piece 3 and the edge of the cover body 1 it is close to is D along the width direction of the cover body 1, where 2.5mm≤D≤1 / 3×B.

[0080] The specific values ​​of B and D for the test results when the battery experiences thermal runaway are shown in Table 4 below:

[0081] Table 4

[0082]

[0083] As can be seen from Table 4, controlling the values ​​of B and D can prevent them from being too small, which would affect the mylar of the electrode group, causing scratches on the mylar and increasing the risk of insulation failure; and can also prevent them from being too large, which would affect the effect of the first connecting piece 3 in supporting the electrode group.

[0084] In some embodiments, a second insulating element 4 and a sealing element 5 are respectively sleeved on the outside of the first pole and the second pole. The second insulating element 4 is located on the side of the cover plate body 1 away from the first insulating element 2, and the sealing element 5 is located between the first insulating element 2 and the second insulating element 4.

[0085] In some embodiments, the side of the explosion-proof valve 11 facing away from the first insulating member 2 is covered with a protective member 6.

[0086] This application also provides a battery, including a battery casing, an electrode assembly, and a cover assembly. The cover assembly is used to cover the opening of the battery casing, the electrode assembly is located inside the battery casing, and the cover assembly is the aforementioned cover assembly.

[0087] In the battery provided in this application embodiment, the second part 32 of the first connecting piece 3 is disposed at the position of the explosion-proof valve 11 of the cover plate body 1, and the first insulating member 2 is located between the cover plate body 1 and the first connecting piece 3. The first connecting piece 3 supports the electrode assembly and prevents the electrode assembly from moving or deforming and blocking the explosion-proof valve 11 during thermal runaway. Through the first gap and the first through hole 321, an exhaust channel is formed between the first connecting piece 3 and the explosion-proof valve 11 to prevent the explosion-proof valve 11 from being blocked and unable to exhaust.

[0088] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0089] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0090] It should also be noted that in the apparatus, equipment, and methods of this application, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions of this application.

[0091] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0092] It should be understood that the qualifying terms “first,” “second,” “third,” “fourth,” “fifth,” and “sixth” used in the description of the embodiments of this application are only used to more clearly illustrate the technical solutions and are not intended to limit the scope of protection of this application.

[0093] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A cover plate assembly, comprising: The cover plate body is equipped with an explosion-proof valve and a first pole column; The first insulating element is disposed on the inner side of the cover plate body; The first connecting piece is located on the side of the first insulating member away from the cover plate body and is electrically connected to the first pole post; The first connecting piece is characterized in that it comprises: The first part, at least a portion of which is electrically connected to the first pole post; The second part is electrically connected to the first part in at least a portion of its area. The second part is located below the explosion-proof valve and has a first gap between it and the explosion-proof valve. The second part is provided with a first through hole.

2. The cover plate assembly according to claim 1, characterized in that, The first connecting piece has a support platform protruding from its side near the first insulating member.

3. The cover plate assembly according to claim 2, characterized in that, The projection of the support platform on the cover plate body is located between the explosion-proof valve and the first pole post, and is relatively close to the explosion-proof valve; And / or, on both sides of the length centerline of the cover plate assembly, a plurality of support platforms are symmetrically arranged on the side of the first connecting piece.

4. The cover plate assembly according to claim 1, characterized in that, The area of ​​the first region enclosed by the grooves of the explosion-proof valve in its plane is S1; In the thickness direction of the cover plate body, the area of ​​the first through hole of the first connecting piece in the first region is S4; In the thickness direction of the cover plate body, the projected area of ​​the first connecting piece in the first region is S5, 0.3≤S4 / S5≤0.

9.

5. The cover plate assembly according to claim 4, characterized in that, In the thickness direction of the cover plate body, the difference between the area S1 of the first region and the projected area S5 of the first connecting piece in the first region is S2. In the thickness direction of the cover plate body, the sum of the air passage areas formed on the first gap by the outer contour lines of the second part that coincide with the projection of the groove of the explosion-proof valve is S3, 0.8≤(S2+S3+S4) / S1≤5.

6. The cover plate assembly according to claim 2, characterized in that, In the thickness direction of the cover plate body, the thickness dimension of the first gap is greater than or equal to the protrusion height of the support platform relative to the first side surface, where the first side surface is the side surface of the first connecting piece close to the cover plate body.

7. The cover plate assembly according to claim 1, characterized in that, Along the length of the cover plate body, the second part is provided with a plurality of first through holes arranged side by side; And / or, in the width direction of the cover plate body, the second part is provided with a plurality of the first through holes arranged side by side.

8. The cover plate assembly according to claim 1, characterized in that, The area of ​​the explosion-proof valve covered by the first insulating element is provided with a second through hole.

9. The cover plate assembly according to claim 1, characterized in that, The cover plate body is also provided with a second pole post and a second connecting piece electrically connected to the second pole post; Along the length of the cover plate body: The second pole and the first pole are located on both sides of the explosion-proof valve, respectively; The gap between the first connecting piece and the second connecting piece is greater than or equal to 10 mm.

10. The cover plate assembly according to claim 1, characterized in that, Along the length of the cover plate body, the distance between the first through hole near the explosion-proof valve and the first through hole near the first pole post is A; Along the length of the cover plate body, the dimension between the projection of the free end of the second part onto the cover plate body and the side of the explosion-proof valve near the first pole post is C, where 4mm≤C≤1.2×A.

11. The cover plate assembly according to claim 1, characterized in that, Along the width direction of the cover plate body, the width of the cover plate assembly is B; Along the width direction of the cover plate body, the distance between the edge of the first connecting piece and the edge of the cover plate body adjacent to it is D, 2.5mm≤D≤1 / 3×B.

12. A battery comprising a battery casing, electrode assembly, and a cover assembly, the cover assembly being used to cover an opening in the battery casing, the electrode assembly being located within the battery casing, characterized in that, The cover plate assembly is any one of the cover plate assemblies according to claims 1-11.

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