Battery cover plate and battery

Abstract

The invention belongs to the technical field of batteries, and discloses a battery cover plate and a battery, the battery cover plate comprises a cover plate body provided with a liquid injection hole, the cover plate body comprises a first surface, a second surface, a liquid injection structure and a reverse ejection groove, the liquid injection structure forms a sinking table on the first surface and forms a boss on the second surface, the liquid injection hole is located in the sinking table, and the reverse ejection groove is located in the boss. The reverse jacking groove is formed in the second surface and annularly formed in the outer side of the boss, and the width size W of the reverse jacking groove is larger than or equal to 0.8 mm and smaller than or equal to 1.2 mm. When punching is conducted in the sinking table, a specific tool is inserted into the reverse jacking groove, so that a large supporting force opposite to the acting force during punching is obtained, the sinking table is prevented from collapsing during punching, the levelness of the sinking table and the perpendicularity of the inner wall after a liquid injection hole is formed are guaranteed, and the punching quality is improved. The sealing nail is tightly attached to the sinking table top and the inner wall of the liquid injection hole, good sealing performance is achieved, the contact area is increased, resistance is improved, and the connection stability and firmness degree after assembly are improved.

Description

Technical Field

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

[0002] As an important part of lithium batteries, the structural design of the battery cover not only affects the basic performance of the battery, such as capacity and charge and discharge efficiency, but is also directly related to the safety and long-term reliability of the battery. The main structural components of the battery cover include conductive electrode columns, bare aluminum plates, insulating parts and explosion-proof valves, etc. The insulating parts are used to insulate the conductive electrode columns, usually made of plastic materials to avoid short circuits caused by contact between the insulating parts and the bare aluminum plates. The explosion-proof valve is used to allow the high-temperature and high-pressure gas inside the battery to break through the explosion-proof valve when thermal runaway occurs inside the battery, thereby achieving the purpose of pressure relief protection.

[0003] The battery cover is also provided with an injection hole for injecting electrolyte into the battery. After the injection operation is completed, a sealing nail is inserted into the injection hole to seal the injection hole to prevent the electrolyte from leaking from the injection hole.

[0004] However, the injection holes on the battery cover are usually made by punching technology at present, and a depression is formed on one side of the battery cover and a boss is formed on the other side of the battery cover. However, the battery cover of this structure will be subjected to a large concentrated force when punching. Under the impact of the large concentrated force, the depression surface collapses radially toward the central axis of the injection hole, which leads to poor horizontality of the depression surface on the one hand, and poor verticality of the inner wall of the injection hole after molding on the other hand. As a result, after the sealing nail is inserted, the sealing nail cannot fit tightly with the depression surface and the inner wall of the injection hole, resulting in poor sealing and easy leakage of electrolyte. Moreover, after entering the high-temperature standing and formation processes, the sealing nail with a small contact area with the injection hole is easily affected by the gas production inside the battery, resulting in the problem of falling off due to small resistance, and the connection stability and firmness are poor. Summary of the invention

[0005] The object of the present invention is to provide a battery cover and a battery with good sealing performance and high connection stability and firmness.

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

[0007] On the one hand, a battery cover is provided, the battery cover comprises a cover body provided with a liquid injection hole, the cover body comprises a first surface, a second surface, a liquid injection structure and a reverse top groove, the liquid injection structure is recessed from the first surface to the second surface, and is used to form a sink on the first surface and a convex platform protruding from the second surface on the second surface, the liquid injection hole is located in the sink, and the reverse top groove is provided on the second surface and is arranged around the outer side of the convex platform;

[0008] The width dimension of the reverse top groove along the first direction is W, and satisfies 0.8mm≤W≤1.2mm.

[0009] Optionally, a depth dimension of the anti-top groove along the second direction is t1, and satisfies 0.2mm≤t1≤0.4mm.

[0010] Optionally, the thickness dimension of the cover plate body is t2, and satisfies 0.1≤t1 / t2≤0.2.

[0011] Optionally, a height dimension of the boss protruding from the second surface along the second direction is t3, and satisfies 0.35≤t3 / t2≤0.6.

[0012] Optionally, a height dimension t3 of the boss protruding from the second surface along the second direction satisfies 0.7 mm≤t3≤1.2 mm.

[0013] Optionally, the depth dimension of the sink is t4, and satisfies (t2-t1-t4)≥0.3mm.

[0014] Optionally, a projection area of ​​the anti-top groove on the sinking platform along the second direction has a width dimension L along the first direction, and satisfies L / W≥0.6.

[0015] Optionally, the injection hole includes a fixed hole section and a guide hole section, the guide hole section is located on the side of the injection hole close to the first surface, the fixed hole section is located on the side of the injection hole close to the second surface, the guide hole section is a trumpet shape with an inner diameter gradually increasing away from the fixed hole section, and the inner wall of the fixed hole section is perpendicular to the first surface.

[0016] Optionally, the boss is in a conical shape with an outer diameter gradually decreasing in a direction approaching the pole group.

[0017] On the other hand, a battery is provided, comprising a battery casing, a pole group and a battery cover as described in any one of the above items, wherein the battery casing is a hollow shell structure with an opening, and the battery cover is covered at the opening of the battery casing and closes the battery casing to form a accommodating cavity for accommodating the pole group.

[0018] Beneficial effects of the present invention:

[0019] The present invention provides a battery cover plate, which is provided with a reverse top groove surrounding the outer side of a boss on the second surface of a cover plate body, and is inserted into the reverse top groove by using a specific tool, so that when a liquid injection hole is formed in a sinking platform by a punching process, a supporting force opposite to the force applied during punching is provided to the cover plate body, and a width dimension W of the reverse top groove along a first direction is limited so as to obtain sufficient supporting force to prevent the sinking platform from collapsing during punching, thereby ensuring the horizontality of the sinking platform and the verticality of the inner wall of the liquid injection hole after the formation, so that after the sealing nail is inserted into the liquid injection hole, it can fit tightly with the sinking platform surface and the inner wall of the liquid injection hole, has good sealing performance, increases the contact area, and improves the resistance, thereby improving the connection stability and firmness of the cover plate body and the sealing nail after assembly.

[0020] The present invention also provides a battery, which, by applying the above-mentioned battery cover, improves the sealing performance, reduces the probability of electrolyte leakage, and improves product quality on the one hand, and avoids the problem of sealing nails falling off during manufacturing, thereby improving the manufacturing yield rate on the other hand. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a partial structural schematic diagram of the battery cover provided by the present invention;

[0022] Figure 2 yes Figure 1 The enlarged plan view of the section I in the middle;

[0023] Figure 3 It is a partial structural schematic diagram of the battery provided by the present invention.

[0024] In the figure:

[0025] 100. battery casing; 200. electrode group;

[0026] 1. Cover plate body; 11. Liquid injection hole; 111. Fixed hole section; 112. Guide hole section; 12. First surface; 13. Second surface; 14. Liquid injection structure; 141. Sink; 142. Boss; 15. Anti-top groove. DETAILED DESCRIPTION

[0027] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0028] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0030] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0031] When the injection hole is made by punching technology, the battery cover will be subjected to a large concentrated force, causing the sunken table formed on the battery cover to collapse radially toward the central axis of the injection hole, resulting in poor horizontality of the sunken table and the verticality of the inner wall of the injection hole after forming. As a result, the sealing nail inserted into the injection hole cannot fit tightly with the sunken table and the inner wall of the injection hole, resulting in poor sealing and connection stability.

[0032] Therefore, in order to improve the horizontality of the countersunk surface during punching and the verticality of the inner wall of the injection hole after forming, the sealing nail inserted into the injection hole can fit tightly with the countersunk surface and the inner wall of the injection hole to improve the sealing and connection stability. This embodiment provides a battery cover, which includes a cover body and a sealing nail. The cover body is provided with an injection hole for electrolyte injection, and the sealing nail is inserted into the injection hole.

[0033] like Figures 1 to 3As shown, the cover body 1 includes a first surface 12, a second surface 13, an injection structure 14 and an anti-top groove 15. The injection structure 14 is recessed from the first surface 12 to the second surface 13 to form a sink 141 on the first surface 12 and a boss 142 protruding from the second surface 13 on the second surface 13. The injection hole 11 is located in the sink 141. The anti-top groove 15 is arranged on the second surface 13 and is ringed on the outer side of the boss 142. The width dimension of the anti-top groove 15 along the first direction is W, and satisfies 0.8mm≤W≤1.2mm.

[0034] By opening an anti-top groove 15 surrounding the outer side of the boss 142 on the second surface 13 of the cover body 1, and using a specific tool to insert into the anti-top groove 15, when the injection hole 11 is formed in the sink 141 by a punching process, a supporting force opposite to the force applied during punching is provided to the cover body 1, and the width dimension W of the anti-top groove 15 along the first direction is limited so as to obtain sufficient supporting force to prevent the sink 141 from collapsing during punching, thereby ensuring the horizontality of the sink 141 and the verticality of the inner wall of the injection hole 11 after forming, so that after the sealing nail is inserted into the injection hole 11, it can fit tightly with the sink surface and the inner wall of the injection hole 11, has better sealing, increases the contact area, and increases the resistance, thereby improving the connection stability and firmness of the cover body 1 and the sealing nail after assembly.

[0035] Among them, the battery cover can be used in many different types of batteries, such as blade batteries, square shell batteries or large cylindrical batteries. In the present embodiment, the battery cover is used in square shell batteries, and even if they are all square shell batteries, there are many types of battery covers, so the layouts of different types of battery covers are also different. Therefore, the formation positions of the boss 142 and the sinker 141 formed on the cover body 1 can be freely adjusted according to actual needs. Since the boss 142 is a structure formed by stamping the sinker 141, the shape of the cross-section of the boss 142 is the same as the shape of the cross-section of the sinker 141, and the cross-sections of the two can be circular, elliptical or polygonal, etc. In the present embodiment, the cross-sectional shapes of both the boss 142 and the sinker 141 are circular, wherein the hole type of the injection hole 11 should be adapted to the cross-sectional shape of the sinker 141. In the present embodiment, since the cross-sectional shape of the sinker 141 is circular, the injection hole 11 is a circular through hole.

[0036] Alternatively, if Figure 1 , Figure 2As shown, the depth dimension of the reverse top groove 15 along the second direction is t1, and satisfies 0.2mm≤t1≤0.4mm. By limiting the depth dimension t1 of the reverse top groove 15 along the second direction to satisfy 0.2mm≤t1≤0.4mm, on the one hand, it is prevented that the depth of the reverse top groove 15 is too shallow, which makes it difficult to be clamped and fixed with the tooling when it is matched with the tooling, and on the other hand, it is prevented that the depth of the reverse top groove 15 is too deep, which reduces the structural strength of the cover body 1 and causes the poor pressure bearing capacity of the cover body 1.

[0037] In this embodiment, the depth dimension t1 of the reverse top groove 15 along the second direction can be any value between 0.2 mm and 0.4 mm or a range between any two values, such as 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, etc.

[0038] Alternatively, if Figure 1 , Figure 2 As shown, the thickness dimension of the cover plate body 1 is t2, and satisfies 0.1≤t1 / t2≤0.2. By limiting the ratio between the depth dimension t1 of the reverse top groove 15 along the second direction and the thickness dimension t2 of the cover plate body 1, so as to satisfy 0.1≤t1 / t2≤0.2, the thickness dimension t2 of the cover plate body 1 can be determined according to the depth dimension t1 of the reverse top groove 15 along the second direction. On the one hand, it is avoided that the thickness of the cover plate body 1 is too small, resulting in weak structural strength, and on the other hand, it is avoided that the thickness of the cover plate body 1 is too large, resulting in an increase in the overall structural size and an increase in manufacturing cost.

[0039] Among them, in order to verify the influence of the setting of the relevant structural dimensions of the reverse top groove 15 of the cover body 1 on the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall after the injection hole 11 is formed, the depth dimension t1 of the reverse top groove 15 along the second direction, the thickness dimension t2 of the cover body 1 and the width dimension W of the reverse top groove 15 along the first direction are set, and a batch of products are prepared according to the set dimensions. If the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of the batch of products is less than 0.01%, it is the optimal structure, and the batch of products meets the design requirements. As shown in Table 1, for the different dimension settings of the depth dimension t1 of the reverse top groove 15 along the second direction, the thickness dimension t2 of the cover body 1 and the width dimension W of the reverse top groove 15 along the first direction, eight groups of embodiments and nine groups of comparative examples are designed, and a total of seventeen batches of products are tested and verified, wherein the number and product specifications of each batch of products are the same.

[0040] Table 1

[0041]

[0042] In Example 1, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.25 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.125. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 0.8 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0071%.

[0043] In Example 2, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.25 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.125. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 0.85 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0067%.

[0044] In Example 3, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.25 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.125. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 0.9 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0051%.

[0045] In Example 4, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.25 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.125. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 1 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0055%.

[0046] In Example 5, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.25 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.125. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 1.1 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0062%.

[0047] In Example 6, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.25 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.125. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 1.2 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0069%.

[0048] In Example 7, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.3 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.15. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 0.85 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0069%.

[0049] In Example 8, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.4 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.2. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 0.85 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0072%.

[0050] It can be seen from Examples 1 to 8 that when the depth dimension t1 of the anti-top groove 15 along the second direction satisfies the range of 0.2mm≤t1≤0.4mm, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 satisfies the range of 0.1≤t1 / t2≤0.2, and the width dimension W of the anti-top groove 15 along the first direction satisfies the range of 0.8mm≤W≤1.2mm, the defective ratios of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products are both less than 0.01%, which meet the optimal design requirements.

[0051] In comparative example 1, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 0 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 1.53%.

[0052] In Comparative Example 2, first, the depth dimension t1 of the anti-top groove 15 along the second direction is set to 0 mm, and then the thickness dimension t2 of the cover body 1 is set to 4 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 0 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 1.27%.

[0053] It can be seen from Comparative Examples 1 and 2 that for the batch of products without the anti-top groove 15 on the cover body 1, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 is far greater than 0.01%.

[0054] In Comparative Example 3, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.15 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.075. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 0.85 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0186%.

[0055] In Comparative Example 4, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.18 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.09. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 0.85 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0167%.

[0056] In comparative example 5, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.45 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.225. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 0.85 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0179%.

[0057] In Comparative Example 6, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.5 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.25. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 0.85 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0147%.

[0058] It can be seen from Comparative Examples 3 to 6 that when the depth dimension t1 of the anti-top groove 15 along the second direction does not satisfy the range of 0.2mm≤t1≤0.4mm, and the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 does not satisfy the range of 0.1≤t1 / t2≤0.2, even if the width dimension W of the anti-top groove 15 along the first direction satisfies the range of 0.8mm≤W≤1.2mm, the defective ratios of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products are both greater than 0.01%, which does not meet the optimal design requirements, but compared with Comparative Examples 1 and 2, the defective ratio is much lower than that when the anti-top groove 15 is not set.

[0059] In comparative example 7, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.25 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.125. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 0.75 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0151%.

[0060] In Comparative Example 8, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.25 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.125. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 1.3 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0159%.

[0061] In comparative example 9, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.25 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.125. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 1.4 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0160%.

[0062] It can be seen from Comparative Examples 7 to 9 that when the width dimension W of the anti-top groove 15 along the first direction does not satisfy the range of 0.8mm≤W≤1.2mm, even if the depth dimension t1 of the anti-top groove 15 along the second direction satisfies the range of 0.2mm≤t1≤0.4mm, and the ratio between the depth dimension t1 of the anti-top groove 15 along the second direction and the thickness dimension t2 of the cover body 1 satisfies the range of 0.1≤t1 / t2≤0.2, the defective ratios of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products are both greater than 0.01%, which does not meet the optimal design requirements, but the defective ratio is much lower than that of Comparative Examples 1 and 2 when the anti-top groove 15 is not set.

[0063] Alternatively, if Figure 1 , Figure 2As shown, the height dimension of the boss 142 protruding from the second surface 13 along the second direction is t3, and satisfies 0.35≤t3 / t2≤0.6. By limiting the ratio between the height dimension t3 of the boss 142 protruding from the second surface 13 along the second direction and the thickness dimension t2 of the cover body 1, so as to satisfy 0.35≤t3 / t2≤0.6, the height of the boss 142 protruding from the second surface 13 can be determined according to the thickness of the cover body 1, thereby avoiding, on the one hand, the short effective matching length between the inner wall of the injection hole 11 and the sealing pin due to the boss 142 protruding from the second surface 13 being too small, and on the other hand, avoiding the boss 142 protruding from the second surface 13 being too large, which causes the boss 142 to occupy a large space, thereby limiting the volume of the pole group 200 and reducing the energy density.

[0064] Specifically, Figure 1 , Figure 2 As shown, the height dimension t3 of the boss 142 protruding from the second surface 13 along the second direction satisfies 0.7 mm ≤ t3 ≤ 1.2 mm. In this embodiment, the height dimension t3 of the boss 142 protruding from the second surface 13 along the second direction can be any value between 0.7 mm and 1.2 mm or a range between any two values, such as 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, etc.

[0065] Alternatively, if Figure 1 , Figure 2 As shown, the depth dimension of the sink 141 is t4, and satisfies (t2-t1-t4)≥0.3mm. By limiting the difference between the thickness dimension t2 of the cover body 1, the depth dimension t1 of the anti-top groove 15 along the second direction, and the depth dimension t4 of the sink 141, the difference between the three satisfies (t2-t1-t4)≥0.3mm, thereby ensuring that after the cover body 1 is provided with the sink 141 and the anti-top groove 15, the remaining area has sufficient material thickness to ensure that the area has sufficient structural strength.

[0066] Optionally, the projection area of ​​the reverse top groove 15 on the sink 141 along the second direction has a width dimension L along the first direction, and satisfies L / W≥0.6. By limiting the ratio between the width dimension L of the projection area of ​​the reverse top groove 15 on the sink 141 along the second direction and the width dimension W of the reverse top groove 15 along the first direction, so that both satisfy L / W≥0.6, it is ensured that when supporting the sink 141, there is a sufficient support area between the tooling for reverse top support and the sink 141, thereby ensuring that the tooling for reverse top support has sufficient support strength for the sink 141 to resist the force during punching.

[0067] Alternatively, if Figure 1 , Figure 2As shown, the injection hole 11 includes a fixed hole section 111 and a guide hole section 112. The guide hole section 112 is located on the side of the injection hole 11 close to the first surface 12, and the fixed hole section 111 is located on the side of the injection hole 11 close to the second surface 13. The guide hole section 112 is trumpet-shaped with the inner diameter gradually increasing away from the fixed hole section 111, and the inner wall of the fixed hole section 111 is perpendicular to the first surface 12. By providing the trumpet-shaped guide hole section 112 on the injection hole 11, the sealing pin is guided to be inserted into the injection hole 11, and by providing the fixed hole section 111 with the inner wall perpendicular to the first surface 12, it is ensured that the inner wall of the fixed hole section 111 is covered on the outer side of the sealing pin, so as to generate a large friction resistance to the sealing pin and prevent the sealing pin from falling off.

[0068] Alternatively, if Figure 1 , Figure 2 As shown, the boss 142 is a tapered shape with an outer diameter gradually decreasing in the direction close to the pole group 200. By setting the boss 142 as a tapered shape with an outer diameter gradually decreasing in the direction close to the pole group 200, it is convenient to use the tapered surface to guide the tooling for the reverse top support to be inserted into the reverse top groove 15.

[0069] In this embodiment, if Figure 3 As shown, a battery is also provided, which includes a battery housing 100, an electrode group 200 and the above-mentioned battery cover, wherein the battery housing 100 is a hollow shell structure with an opening, and the battery cover is provided at the opening of the battery housing 100 and closes the battery housing 100 to form a receiving cavity for accommodating the electrode group 200. By applying the above-mentioned battery cover, the battery improves the sealing performance, reduces the probability of electrolyte leakage, and improves the product quality, and avoids the problem of sealing nails falling off during manufacturing, thereby improving the manufacturing yield rate.

[0070] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A battery cover, comprising a cover body provided with a liquid injection hole, characterized in that: The cover body comprises a first surface, a second surface, a liquid injection structure and an anti-top groove, wherein the liquid injection structure is recessed from the first surface to the second surface, and is used to form a sink on the first surface and a convex platform protruding from the second surface on the second surface, the liquid injection hole is located in the sink, and the anti-top groove is arranged on the second surface and is arranged around the outer side of the convex platform; The width dimension of the reverse top groove along the first direction is W, and satisfies 0.8mm≤W≤1.2mm.

2. The battery cover according to claim 1, characterized in that: The depth dimension of the reverse top groove along the second direction is t1, and satisfies 0.2mm≤t1≤0.4mm.

3. The battery cover according to claim 1, characterized in that: The thickness dimension of the cover plate body is t2, and satisfies 0.1≤t1 / t2≤0.

2.

4. The battery cover according to claim 3, characterized in that: A height dimension of the boss protruding from the second surface along the second direction is t3, and satisfies 0.35≤t3 / t2≤0.

6.

5. The battery cover according to claim 4, characterized in that: A height dimension t3 of the boss protruding from the second surface along the second direction satisfies 0.7 mm≤t3≤1.2 mm.

6. The battery cover according to claim 3, characterized in that: The depth dimension of the sink is t4, and satisfies (t2-t1-t4)≥0.3mm.

7. The battery cover according to claim 1, characterized in that: The projection area of ​​the anti-top groove on the sinking platform along the second direction has a width dimension L along the first direction, and satisfies L / W≥0.

6.

8. The battery cover according to claim 1, characterized in that: The injection hole includes a fixed hole section and a guide hole section, the guide hole section is located on the side of the injection hole close to the first surface, the fixed hole section is located on the side of the injection hole close to the second surface, the guide hole section is a trumpet shape with an inner diameter gradually increasing away from the fixed hole section, and the inner wall of the fixed hole section is perpendicular to the first surface.

9. The battery cover according to claim 1, characterized in that: The boss is in a tapered shape with an outer diameter gradually decreasing in a direction approaching the pole group.

10. A battery, characterized in that The battery comprises a battery casing, a pole group and a battery cover as described in any one of claims 1 to 9, wherein the battery casing is a hollow shell structure with an opening, and the battery cover is arranged on the opening of the battery casing and closes the battery casing to form a receiving cavity for accommodating the pole group.

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