A cover plate assembly and battery cell

Abstract

The application provides a cover plate assembly and a battery cell. The cover plate assembly comprises: a top cover comprising a cover plate body and a liquid injection area recessed in a first direction relative to the cover plate body, wherein a through liquid injection hole is arranged on the liquid injection area, and a circumferential groove is arranged around the liquid injection area on the cover plate body; a sealing nail comprising a connecting area and a sealing area recessed in the first direction relative to the connecting area, wherein the connecting area is connected to the circumferential groove, and the sealing area is used to cover the liquid injection hole; wherein the cover plate body comprises oppositely arranged first and second plate surfaces, and the first direction is a direction from the first plate surface to the second plate surface. The connecting area in the circumferential groove can realize quick positioning of the sealing nail and the top cover, so as to improve the welding efficiency of the sealing nail and the top cover.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a cover plate assembly and a battery cell. Background Technology

[0002] The top cover of the battery cell has a liquid injection hole. The top cover needs to be fixed to the liquid injection hole by welding with a sealing nail to achieve the seal. However, the welding effect and welding efficiency between the sealing nail and the top cover need to be further improved. Utility Model Content

[0003] In view of this, the purpose of this utility model is to provide a cover plate assembly and a battery cell to solve at least some of the technical problems in the background art.

[0004] To achieve the above objectives, this utility model provides a cover plate assembly, comprising:

[0005] The top cover includes a cover plate body and an injection area recessed in a first direction relative to the cover plate body. The injection area is provided with a through injection hole, and the cover plate body is provided with an circumferential groove around the injection area.

[0006] A sealing pin includes a connecting area and a sealing area recessed in a first direction relative to the connecting area, the connecting area being connected within the circumferential groove, and the sealing area being used to cover the injection hole;

[0007] The cover plate body includes a first plate surface and a second plate surface arranged opposite to each other, and the first direction is the direction from the first plate surface to the second plate surface.

[0008] Furthermore, a portion of the sealing area protrudes in the second direction to form a protrusion, and at least a portion of the protrusion is used to cover the injection hole;

[0009] The second direction is opposite to the first direction.

[0010] Furthermore, the height of the side of the protrusion away from the injection hole in the second direction is equal to or less than the height of the first plate surface.

[0011] Furthermore, the injection area includes a first transition portion and a first recessed portion connected to each other. The first recessed portion is parallel to the cover plate body, and the injection hole is located on the first recessed portion. The first transition portion is connected to the cover plate body. A first included angle is formed between the first transition portion and the first recessed portion.

[0012] The sealing area includes a second transition portion and a second recessed portion connected to each other. The second recessed portion is parallel to the cover plate body and is used to cover the injection hole. The second transition portion is connected to the connecting area. A second included angle is formed between the second transition portion and the second recessed portion.

[0013] Wherein, the first included angle is smaller than the second included angle, and both the first included angle and the second included angle are greater than 90°.

[0014] Furthermore, the protrusion includes a buffer section and a parallel section connected to each other, the parallel section being parallel to the bottom of the sealing area; a third included angle is formed between the buffer section and the parallel section, the third included angle being greater than 90°.

[0015] Furthermore, the second plate surface is provided with an annular groove surrounding the injection area.

[0016] Furthermore, the injection hole is located in the central region of the injection area.

[0017] Furthermore, the width of the connection area is 0.8 to 2 millimeters.

[0018] Furthermore, the side of the connecting area away from the second plate surface is flush with the first plate surface.

[0019] Based on the same inventive concept, this application also provides a battery cell, comprising:

[0020] The cover plate assembly as described above;

[0021] The outer casing, the cover plate assembly is connected to the outer casing and forms a receiving space, and the injection hole is in communication with the receiving space.

[0022] As can be seen from the above description, the cover plate assembly and battery cell provided by this utility model have a liquid injection area recessed in a first direction on the main body of the top cover. The liquid injection area has a liquid injection hole. The sealing pin includes a connecting area and a sealing area recessed in the first direction relative to the connecting area. The sealing area is used to cover the liquid injection hole on the liquid injection area, and the connecting area is used to connect with the main body of the cover plate. By setting an circumferential groove around the liquid injection area on the main body of the cover plate, the connecting area is located in the circumferential groove on the main body of the cover plate. The connecting area and the circumferential groove are connected by welding. That is, by the connecting area being located in the circumferential groove, the sealing pin and the top cover can be quickly positioned, thereby improving the welding efficiency of the sealing pin and the top cover. In addition, the sealing area is recessed in the first direction relative to the connecting area, so that there is a clear dividing line between the sealing area and the connecting area, which facilitates the quick determination of the welding area and further improves the welding efficiency of the sealing pin and the top cover. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model 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 some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a three-dimensional structural diagram of the battery cell according to an embodiment of the present invention;

[0025] Figure 2 This is a top view of the battery cell according to an embodiment of the present invention;

[0026] Figure 3 for Figure 2 Schematic diagram of the partial cross-sectional structure of the cover plate assembly in the AA direction Figure 1 ;

[0027] Figure 4 for Figure 2 Schematic diagram of the partial cross-sectional structure of the cover plate assembly in the AA direction Figure 2 ;

[0028] Figure 5 This is a partial cross-sectional structural diagram of the top cover according to an embodiment of the present invention;

[0029] Figure 6 This is a partial cross-sectional structural diagram of the sealing nail according to an embodiment of the present invention.

[0030] In the above diagram, the X-arrow indicates the first direction, and the Y-arrow indicates the second direction;

[0031] In the diagram: 001, cover plate assembly; 002, outer shell; 100, top cover; 110, cover plate body; 111, first plate surface; 112, second plate surface; 113, circumferential groove; 114, annular groove; 120, liquid injection area; 121, liquid injection hole; 122, first transition section; 123, first recessed section; 200, sealing pin; 210, connecting area; 220, sealing area; 221, protrusion; 2211, buffer section; 2212, parallel section; 222, second transition section; 223, second recessed section; 300, electrolyte buffer space; 400, clearance space. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0033] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this utility model should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the term encompasses the elements or objects listed following the term and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0034] In related technologies, such as Figure 1 As shown, the battery cell includes a cover plate assembly 001 and a housing 002. The cover plate assembly 001 is connected to the housing 002, forming a receiving space. A bare battery cell is disposed within the receiving space. An injection hole 121 on the cover plate assembly 001 communicates with the receiving space to inject electrolyte into it. After the electrolyte injection is complete, the top cover 100 in the cover plate assembly 001 needs to be welded to a sealing pin 200 to seal the injection hole 121. However, if the sealing pin 200 cannot be quickly placed in a suitable position outside the injection hole 121, or if the welding area cannot be quickly determined during welding, the welding efficiency between the sealing pin 200 and the top cover 100 will be affected.

[0035] Based on the above issues, the applicant discovered that an circumferential groove 113 can be provided on the top cover 100 so that the connection area 210 of the sealing nail 200 is located within the circumferential groove 113. The circumferential groove 113 enables rapid positioning of the connection area 210 of the sealing nail 200, which can effectively improve the welding efficiency of the sealing nail 200 and the top cover 100.

[0036] The present application will be described in detail below through one or more specific embodiments.

[0037] In some embodiments, a cover assembly 001, such as Figure 1 , Figure 2 and Figure 3 As shown, it includes:

[0038] The top cover 100 includes a cover plate body 110 and an injection area 120 recessed in a first direction X relative to the cover plate body 110. The injection area 120 is provided with a through injection hole 121, and the cover plate body 110 is provided with an circumferential groove 113 around the injection area 120.

[0039] The sealing pin 200 includes a connecting area 210 and a sealing area 220 recessed in a first direction X relative to the connecting area 210. The connecting area 210 is connected to the circumferential groove 113, and the sealing area 220 is used to cover the injection hole 121.

[0040] The cover plate body 110 includes a first plate surface 111 and a second plate surface 112 disposed opposite to each other, and the first direction X is the direction from the first plate surface 111 to the second plate surface 112.

[0041] Specifically, the top cover 100 and the sealing nail 200 can both be made of stainless steel. This stainless steel material can reduce the weight of the battery cell while ensuring the strength of the top cover 100 and the sealing nail 200, and can also ensure the welding yield and welding strength of the sealing nail 200 and the top cover 100.

[0042] Specifically, the thickness of the sealing stud 200 is less than the thickness of the top cover 100 to reduce the weight load exerted by the sealing stud 200 on the top cover 100. For example, the thickness of the top cover 100 ranges from 0.3 to 3 mm, and more optionally, the thickness ranges from 0.5 to 0.8 mm. The thickness of the sealing stud 200 ranges from 0.1 to 2 mm, and more optionally, the thickness ranges from 0.2 to 0.5 mm.

[0043] Specifically, the first plate surface 111 of the cover plate body 110 is the outer surface of the cover plate body 110, that is, the side of the bare battery cell away from the battery cell. Correspondingly, the second plate surface 112, which is opposite to the first plate surface 111, is the side of the cover plate body 110 close to the bare battery cell. The sealing nail 200 is located on one side of the first plate surface 111 of the cover plate body 110 and is connected to the first plate surface 111 of the cover plate body 110, that is, the connection area 210 of the sealing nail 200 is connected to the first plate surface 111 of the cover plate body 110. The first direction X is the direction from the first plate surface 111 to the second plate surface 112.

[0044] The injection area 120 is recessed in the first direction X relative to the cover plate body 110, and the injection hole 121 is located on the injection area 120, such that the injection hole 121 is recessed relative to the outer surface (i.e. the first plate surface 111) of the cover plate body 110. The cover plate body 110 protects the injection hole 121 to prevent the injection hole 121 from directly contacting external forces, causing wear on the injection hole 121, and resulting in electrolyte leakage.

[0045] The sealing area 220 is recessed in the first direction X relative to the connecting area 210. The connecting area 210 protects the sealing area 220, preventing it from directly contacting external forces and causing wear, which would affect its sealing performance over the injection hole 121. Furthermore, the recess of the sealing area 220 relative to the connecting area 210 in the first direction X also creates a clear boundary between them, facilitating the welding positioning of the connecting area 210 and the circumferential groove 113, and further improving the welding efficiency of the sealing pin 200 and the top cover 100. Furthermore, the sealing area 220 is recessed in the first direction X relative to the connecting area 210, so that the connection between the sealing area 220 and the connecting area 210 cooperates with the connection between the circumferential groove 113 of the cover plate body 110 and the liquid injection area 120 (which can be a snap-fit ​​or abutment fit), which is beneficial to the positioning stability of the sealing nail 200 on the top cover 100, and thus helps to improve the welding efficiency of the sealing nail 200 on the top cover 100.

[0046] The circumferential groove 113 is disposed around the injection area 120 and is located on the first plate surface 111 of the cover plate body 110, so that the connection area 210 of the sealing nail 200 is located in the circumferential groove 113, and the side of the circumferential groove 113 near the injection area 120 is connected to the injection area 120, so that the sealing area 220 connected to the connection area 210 can extend relative to the circumferential groove 113 to cover the injection hole 121.

[0047] In this embodiment, the cover plate body 110 of the top cover 100 is provided with an injection area 120 recessed in the first direction X, and an injection hole 121 is provided in the injection area 120. The sealing nail 200 includes a connecting area 210 and a sealing area 220 recessed in the first direction X relative to the connecting area 210. The sealing area 220 is used to cover the injection hole 121 on the injection area 120, and the connecting area 210 is used to connect with the cover plate body 110. By providing an circumferential groove 113 around the injection area 120 on the cover plate body 110, the connecting area 210 is located in the annular groove 114 on the cover plate body 110. The connecting area 210 and the annular groove 113 are connected by welding. That is, by the connecting area 210 being located in the annular groove 113, the sealing nail 200 and the top cover 100 can be quickly positioned, thereby improving the welding efficiency of the sealing nail 200 and the top cover 100. In addition, the sealing area 220 is recessed relative to the connecting area 210 in the first direction X, so that there is a clear dividing line between the sealing area 220 and the connecting area 210, which facilitates the quick determination of the welding area and further improves the welding efficiency of the sealing nail 200 and the top cover 100.

[0048] In some embodiments, such as Figure 4 As shown, a portion of the sealing area 220 protrudes in the second direction Y to form a protrusion 221, and at least a portion of the protrusion 221 is used to cover the injection hole 121;

[0049] Wherein, the second direction Y is opposite to the first direction X.

[0050] Specifically, the sealing area 220 is a region recessed in the first direction X relative to the connecting area 210, which includes a second transition portion 222 and a second recessed portion 223, wherein one end of the second transition portion 222 is connected to the connecting area 210 and the other end is connected to the second recessed portion 223, and a portion of the second recessed portion 223 protrudes in the second direction Y.

[0051] The second direction Y is the direction from the second plate surface 112 to the first plate surface 111, which is opposite to the recessed direction of the sealing area 220. A portion of the sealing area 220 protrudes in the second direction Y to form a protrusion 221, which can reduce the bottom size of the sealing area 220, thereby reducing the pit on the outer surface of the cover plate assembly 001. This is beneficial to improving the flatness and strength of the outer surface of the cover plate assembly 001, and facilitates the stacking, storage and transportation of the battery cells corresponding to the cover plate assembly 001.

[0052] Furthermore, at least a portion of the protrusion 221 covers the injection hole 121, that is, the protrusion 221 has a portion corresponding to the injection hole 121, which increases the distance between the sealing area 220 and the injection hole 121. An electrolyte buffer space 300 is formed between the protrusion 221 and the injection hole 121. The provision of the electrolyte buffer space 300 increases the electrolyte storage space and can effectively extend the service life of the battery cell.

[0053] In some embodiments, the height of the side of the protrusion 221 away from the injection hole 121 in the second direction Y is equal to or less than the height of the first plate surface 111.

[0054] Specifically, the height of the side of the protrusion 221 away from the injection hole 121 in the second direction Y is equal to or less than the height of the first plate surface 111. That is, the side of the protrusion 221 away from the injection hole 121 is flush with or recessed relative to the first plate surface 111 (outer surface) of the cover plate body 110. This can prevent the protrusion 221 from bearing the pressure from the outside alone, thereby reducing the wear of the protrusion 221 and facilitating the sealing of the injection hole 121 by the sealing nail 200.

[0055] In some embodiments, such as Figure 3 , Figure 5 and Figure 6 As shown, the injection area 120 includes a first transition portion 122 and a first recessed portion 123 connected to each other. The first recessed portion 123 is parallel to the cover plate body 110. The injection hole 121 is located on the first recessed portion 123. The first transition portion 122 is connected to the cover plate body 110. A first included angle α is formed between the first transition portion 122 and the first recessed portion 123.

[0056] The sealing area 220 includes a second transition portion 222 and a second recessed portion 223 connected to each other. The second recessed portion 223 is parallel to the cover plate body 110 and is used to cover the injection hole 121. The second transition portion 222 is connected to the connecting area 210. A second included angle β is formed between the second transition portion 222 and the second recessed portion 223.

[0057] Wherein, the first included angle α is smaller than the second included angle β, and both the first included angle α and the second included angle β are greater than 90°.

[0058] Specifically, a first included angle α is formed between the first transition portion 122 and the first recessed portion 123, and a second included angle β is formed between the second transition portion 222 and the second recessed portion 223, wherein the first included angle α is smaller than the second included angle β. The setting that the first included angle α is smaller than the second included angle β provides a fitting tolerance for the installation of the sealing pin 200 onto the top cover 100, reducing the assembly time of the sealing pin 200 on the top cover 100, thereby improving the assembly efficiency of the sealing pin 200 on the top cover 100.

[0059] Furthermore, both the first included angle α and the second included angle β are greater than 90°, meaning that the bending angles of the first recessed portion 123 relative to the first transition portion 122 and the second recessed portion 223 relative to the second transition portion 222 are relatively large. This effectively reduces the bending stress between the first transition portion 122 and the first recessed portion 123, as well as between the second transition portion 222 and the second recessed portion 223. Moreover, since both the first included angle α and the second included angle β are greater than 90°, it also indicates that their corresponding angles α' (i.e., the recessed angle of the injection area 120 relative to the cover plate body 110) and β' (i.e., the recessed angle of the sealing area 220 relative to the connecting area 210) are also greater than 90°. This means that the recessed angles are relatively large, further reducing the bending stress between the injection area 120 and the cover plate body 110, and between the sealing area 220 and the connecting area 210. This, in turn, better maintains the overall strength of the sealing nail 200 and the top cover 100.

[0060] In some embodiments, such as Figure 3 , Figure 4 , Figure 5and Figure 6 As shown, the protrusion 221 includes a buffer section 2211 and a parallel section 2212 connected to each other. The parallel section 2212 is parallel to the bottom of the sealing area 220. A third included angle θ is formed between the buffer section 2211 and the parallel section 2212. The third included angle θ is greater than 90°.

[0061] Specifically, the third included angle θ is greater than 90°, which means that its corresponding angle θ' (i.e., the protrusion angle of the protrusion 221 relative to the sealing area 220) is also greater than 90°. This makes the bending stress between the protrusion 221 and the sealing area 220, as well as the bending stress between the parallel section 2212 and the buffer section 2211, smaller, thereby better maintaining the overall strength of the sealing nail 200.

[0062] In some embodiments, such as Figure 3 and Figure 4 As shown, there is a gap between the connecting area 210 and the sidewall of the circumferential groove 113.

[0063] Specifically, the side of the circumferential groove 113 near the injection area 120 is connected to the injection area 120, so the side of the circumferential groove 113 near the injection area 120 has no sidewall. In this embodiment, the sidewall of the circumferential groove 113 is the sidewall of the circumferential groove 113 away from the injection area 120.

[0064] The connecting area 210 is located within the circumferential groove 113 and is welded and fixed to the circumferential groove 113. There is a gap L1 between the connecting area 210 and the side wall of the circumferential groove 113, which ensures that the path of the connecting area 210 into the circumferential groove 113 is unobstructed, facilitating the rapid positioning of the sealing nail 200 and the top cover 100 within the circumferential groove 113, thereby improving the welding efficiency of the sealing nail 200 and the top cover 100.

[0065] In some embodiments, the injection hole 121 is located in the central region of the injection area 120.

[0066] Specifically, both the injection hole 121 and the injection area 120 are circular in shape. The circumferential groove 113 surrounds the injection area 120 and is also circular in shape. The circumferential groove 113 and the injection area 120 (the area outside the injection hole 121) are arranged sequentially around the injection hole 121 to protect it. Positioning the injection hole 121 in the center of the injection area 120 ensures that the centers of the injection hole 121, the injection area 120, and the circumferential groove 113 coincide. This facilitates the placement of the injection hole 121 and ensures that the protective effect of the circumferential groove 113 and the injection area 120 on the injection hole 121 is uniform, thus improving the practicality of the top cover 100.

[0067] In some embodiments, such as Figure 3 and Figure 4 As shown, the second plate surface 112 is provided with an annular groove 114 surrounding the injection area 120.

[0068] Specifically, the second plate surface 112 is one side of the cover plate body near the bare battery cell. The annular groove 114 is provided around the side of the liquid injection area 120 near the bare battery cell. The side of the liquid injection area 120 near the bare battery cell is the side that protrudes relative to the second plate surface 112 in the first direction X. The liquid injection area 120 and the cover plate body 110 are integrally formed. The liquid injection area 120 is formed by stamping on the cover plate body 110. Correspondingly, there is bending stress between the liquid injection area 120 and the second plate surface 112. The setting of the annular groove 114 can reduce the bending stress of the cover plate body 110 around the liquid injection area 120, and avoid the cover plate body 110 from affecting its relative position with the liquid injection area 120 under the action of bending stress. This is beneficial to the stability of the top cover 100, and thus beneficial to the stability of the cover plate assembly 001.

[0069] In addition, the depth of the annular groove 114 is small, within 0.1 mm.

[0070] In some embodiments, the injection hole 121 is located in the central region of the orthogonal projection of the protrusion 221 onto the injection area 120.

[0071] Specifically, the injection hole 121 is located on the injection area 120, and the injection hole 121 is located in the center area of ​​the orthogonal projection of the protrusion 221 on the injection area 120. That is, the protrusion 221 is directly opposite to the injection hole 121, and the protrusion 221 uniformly covers the injection hole 121. The area between the protrusion 221 and the injection hole 121 is the electrolyte buffer space 300. The protrusion 221 uniformly covers the injection hole 121, making the electrolyte buffer space 300 and the injection hole 121 uniformly connected. This ensures that the process of electrolyte flowing into or out of the electrolyte buffer space 300 through the injection hole 121 is uniform, thereby making the buffering force of the electrolyte on the protrusion 221 uniform. This avoids damage to the protrusion 221 due to uneven electrolyte action, which helps to extend the service life of the protrusion 221 and the sealing nail 200, and thus improves the practicality of the cover plate assembly 001.

[0072] In some embodiments, such as Figure 3 As shown, the width of the connection area 210 is 0.8~2 mm.

[0073] Specifically, the connection between the connecting area 210 and the cover plate body 110 is by welding. To ensure the welding strength, the width L2 of the connecting area 210 is 0.8~2mm.

[0074] In some embodiments, the sealing area 220 has a clearance 400 between one side of the sealing area 220 near the injection hole 121 and the injection hole 121, and the clearance 400 is 0.1 to 3 mm.

[0075] Specifically, the clearance 400 can prevent the sealing area 220 from contacting the injection hole 121, thereby reducing the assembly time of the sealing pin 200 on the top cover 100, which in turn helps to improve the assembly efficiency and welding efficiency of the sealing pin 200 on the top cover 100, and is conducive to its widespread application.

[0076] If the clearance 400 is too large, it will affect the positioning of the sealing nail 200 on the top cover 100. Therefore, the clearance 400 is generally 0.1~3mm.

[0077] For example, the distance of the clearance 400 is 2 mm.

[0078] In some embodiments, the side of the connection area 210 away from the second plate surface 112 is flush with the first plate surface 111.

[0079] Specifically, the height of the connecting area 210 is the same as the height of the circumferential groove 113, which can improve the flatness of the outer surface (i.e., the first plate surface 111) of the cover plate body 110 and reduce the influence of the circumferential groove 113 on the strength of the cover plate body 110.

[0080] In some embodiments, the roughness of the side of the connection area 210 away from the cover plate body 110 is greater than or equal to 0.4 μm. It should be noted that welding the sealing nail 200 to the cover plate body 110 typically uses laser welding. During laser welding, if the surface of the sealing nail 200 (especially the surface of the connection area 210) is smooth, the absorption rate of the laser is low, resulting in a large amount of laser light being reflected, i.e., a "high reflection phenomenon." This reflected laser light can re-enter the output head of the welding equipment, and some of the reflected light may even couple into the energy transmission fiber, propagating in the reverse direction along the fiber to the laser's interior, causing the core components inside the laser to maintain a high temperature, thereby affecting the welding effect and equipment lifespan. Therefore, the roughness of the surface of the connection area 210 can be increased. This surface roughness can be achieved through grinding, embossing, passivation, matte finishing, etc., to avoid the high reflection phenomenon during welding of the sealing nail 200 to the cover plate body 110.

[0081] Based on the same inventive concept, this application also provides a battery cell, such as... Figure 1 As shown, it includes:

[0082] The cover assembly 001 as described above;

[0083] The outer casing 002, the cover plate assembly 001 is connected to the outer casing 002 and forms a receiving space, and the liquid injection hole 121 is in communication with the receiving space.

[0084] The beneficial effects of the battery cell are the same as those of the cover plate assembly 001 described above, and will not be repeated here.

[0085] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application (including the claims) is limited to these examples; within the scope of this invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of this invention as described above, which are not provided in the details for the sake of brevity.

[0086] The embodiments of this utility model are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A cover plate assembly, characterized in that, include: The top cover includes a cover plate body and an injection area recessed in a first direction relative to the cover plate body. The injection area is provided with a through injection hole, and the cover plate body is provided with an circumferential groove around the injection area. A sealing pin includes a connecting area and a sealing area recessed in a first direction relative to the connecting area, the connecting area being connected within the circumferential groove, and the sealing area being used to cover the injection hole; The side of the injection area away from the sealing pin protrudes in a first direction relative to the cover plate body; The cover plate body includes a first plate surface and a second plate surface arranged opposite to each other. The first direction is the direction from the first plate surface to the second plate surface. The second plate surface is provided with an annular groove surrounding the injection area. The injection area includes a first transition portion and a first recessed portion connected together. The first recessed portion is parallel to the cover plate body, and the injection hole is located on the first recessed portion. The first transition portion is connected to the cover plate body. A first angle is formed between the first transition portion and the first recessed portion. The sealing area includes a second transition portion and a second recessed portion connected together. The second recessed portion is parallel to the cover plate body and is used to cover the injection hole. The second transition portion is connected to the connecting area. A second angle is formed between the second transition portion and the second recessed portion. The first angle is smaller than the second angle, and both the first angle and the second angle are greater than 90°. The width of the connection area is 0.8~2 mm; The roughness of the side of the connection area away from the cover plate body is greater than or equal to 0.4 μm.

2. The cover plate assembly according to claim 1, characterized in that, A portion of the sealing area protrudes in the second direction to form a protrusion, and at least a portion of the protrusion is used to cover the injection hole; The second direction is opposite to the first direction.

3. The cover plate assembly according to claim 2, characterized in that, The height of the side of the protrusion away from the injection hole in the second direction is equal to or less than the height of the first plate surface.

4. The cover plate assembly according to claim 2, characterized in that, The protrusion includes a buffer section and a parallel section connected to each other, the parallel section being parallel to the bottom of the sealing area; a third included angle is formed between the buffer section and the parallel section, the third included angle being greater than 90°.

5. The cover plate assembly according to claim 1, characterized in that, The injection hole is located in the central area of ​​the injection zone.

6. The cover plate assembly according to claim 1, characterized in that, The side of the connecting area away from the second plate surface is flush with the first plate surface.

7. A battery cell, characterized in that, include: The cover plate assembly as described in any one of claims 1 to 6; The outer casing, the cover plate assembly is connected to the outer casing and forms a receiving space, and the injection hole is in communication with the receiving space.

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