Cover plate assembly and battery cell

Abstract

The utility model provides a cover plate assembly, comprising: a top cover comprising a cover plate main body and a liquid injection area recessed in a first direction relative to the cover plate main body, the liquid injection area being provided with a through liquid injection hole; the sealing nail comprises a connecting area and a positioning area, the connecting area and the positioning area are connected, the positioning area is sunken in the first direction relative to the connecting area, the connecting area is connected with the cover plate body, the positioning area is used for covering the liquid injection hole, and a part of the positioning area protrudes in the second direction to form a sealing part; a matching structure is formed between the sealing part and the edge of the positioning area, and the matching structure is matched with the liquid injection area, so that the relative positions of the sealing nail and the top cover are fixed. The top cover and the sealing nail can be quickly positioned through clamping matching of the matching structure and the groove, so that the assembling efficiency of the sealing nail and the top cover is improved.

Description

Technical Field

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

[0002] The top cover of the battery cell has an injection hole. The top cover needs to be fixed to the injection hole by welding with a sealing pin to achieve the seal. However, the welding effect and welding efficiency between the sealing pin 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 being provided with a through injection hole;

[0006] A sealing pin includes a connecting area and a positioning area recessed in a first direction relative to the connecting area. The connecting area is connected to the cover plate body, and the positioning area is used to cover the injection hole. A portion of the positioning area protrudes in a second direction to form a sealing part. A mating structure is formed between the sealing part and the edge of the positioning area. The mating structure mates with the injection area to fix the relative position of the sealing pin and the top cover.

[0007] 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, and the first direction is opposite to the second direction.

[0008] Furthermore, a portion of the injection area protrudes in the second direction to form a protrusion, and a groove is formed between the protrusion and the edge of the injection area. The mating structure mates with the groove to fix the relative positions of the sealing pin and the top cover.

[0009] Furthermore, both the groove and the mating structure are annular structures.

[0010] Furthermore, the injection hole is located on the protrusion, and the sealing portion is used to cover the injection hole.

[0011] Furthermore, both the mating structure and the groove have a π-shaped axial section.

[0012] Furthermore, the height of the side of the sealing portion away from the protrusion in the second direction is equal to or higher than the height of the side of the connecting area away from the cover plate body.

[0013] Furthermore, the axial section of the mating structure is a V-shaped structure, and the axial section of the groove is a ︺-shaped structure.

[0014] Furthermore, the height of the side of the sealing portion away from the protrusion in the second direction is lower than the height of the side of the connecting area away from the cover plate body.

[0015] Furthermore, the height of the cover plate body in the second direction is higher than that of the protrusion.

[0016] Based on the same inventive concept, this application also provides a battery cell, comprising:

[0017] The cover plate assembly as described above;

[0018] 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.

[0019] 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 cover plate body of the top cover, and a liquid injection hole is provided in the liquid injection area. The connecting area of ​​the sealing pin is connected to the cover plate body, and a positioning area recessed in the first direction is provided in the connecting area of ​​the sealing pin. The part opposite to the protruding part of the positioning area protrudes in a second direction to form a sealing part. A mating structure is formed between the edge of the sealing part and the connecting area. The mating structure and the liquid injection area fit together to fix the relative position of the sealing pin and the top cover, realizing the rapid positioning of the top cover and the sealing pin, thereby improving the welding efficiency of the sealing pin and the top cover. In addition, the sealing effect of the sealing pin on the liquid injection hole on the top cover is achieved by welding the connecting area of ​​the sealing pin to the cover plate body. During the welding process, the connecting area and the corresponding area on the cover plate body are the welding area. The mating structure is located between the welding area and the sealing part, which facilitates the rapid determination of the welding area and further improves the welding efficiency. Furthermore, the sealing part on the sealing pin can reduce the opening size of the positioning area, thereby reducing the pit on the outer surface of the sealing pin, which helps to improve the flatness of the outer surface of the cover plate assembly. Attached Figure Description

[0020] 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.

[0021] Figure 1 This is a three-dimensional structural diagram of the battery cell according to an embodiment of the present invention;

[0022] Figure 2 This is a top view of the battery cell according to an embodiment of the present invention;

[0023] Figure 3 for Figure 2 Schematic diagram of the partial cross-sectional structure of the cover plate assembly in the AA direction Figure 1 ;

[0024] Figure 4 for Figure 2 Schematic diagram of the partial cross-sectional structure of the cover plate assembly in the AA direction Figure 2 ;

[0025] Figure 5 for Figure 2 A partial cross-sectional view of the top cover in the AA direction;

[0026] Figure 6 for Figure 2 A schematic diagram of the partial cross-sectional structure of the sealing nail in the AA direction.

[0027] In the above diagram, the X-arrow indicates the first direction, and the Y-arrow indicates the second direction;

[0028] In the diagram: 01, cover plate assembly; 02, outer shell; 10, top cover; 11, cover plate body; 111, first plate surface; 112, second plate surface; 12, injection area; 121, protrusion; 122, groove; 13, injection hole; 20, sealing pin; 21, connection area; 22, positioning area; 221, sealing part; 222, mating structure; 30, clearance. Detailed Implementation

[0029] 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.

[0030] 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.

[0031] In related technologies, such as Figure 1 As shown, the battery cell includes a cover plate assembly 01 and a housing 02. The cover plate assembly 01 is connected to the housing 02, forming a receiving space. A bare battery cell is placed in the receiving space. The electrolyte injection hole 13 on the cover plate assembly 01 communicates with the receiving space to inject electrolyte into the receiving space. After the electrolyte is injected, the top cover 10 in the cover plate assembly 01 needs to be welded to the sealing nail 20 to seal the electrolyte injection hole 13. However, if the sealing nail 20 cannot be quickly placed in a suitable position outside the electrolyte injection hole 13, or if the welding area cannot be quickly determined during the welding process, the welding efficiency between the sealing nail 20 and the top cover 10 will be affected. In addition, if welding spatter enters the electrolyte injection hole 13 during the welding process, it will contaminate the electrolyte, thereby affecting the service life of the battery cell. That is, if welding spatter enters the electrolyte injection hole 13, it will affect the welding effect between the sealing nail 20 and the top cover 10.

[0032] Based on the above issues, the applicant discovered that by providing a groove 122 on the top cover 10 and a corresponding mating structure 222 on the sealing nail 20, the top cover 10 and the sealing nail 20 can be quickly positioned through the snap-fit ​​engagement of the mating structure 222 and the groove 122. This positioning function continues throughout the entire welding process, effectively improving welding efficiency. Furthermore, the mating structure 222 serves as the boundary between the connecting area 21 of the sealing nail 20 and the sealing portion 221, allowing welders to quickly position the connecting area 21 of the sealing nail 20, further improving connection and assembly efficiency. Additionally, the groove 122 separates the connecting area 21 of the top cover 10 from the injection hole 13, effectively preventing welding spatter from entering the injection hole 13, thus ensuring welding quality.

[0033] The technical solution of this application will be described in detail below through one or more specific embodiments.

[0034] In some embodiments, a cover assembly 01, such as Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, it includes:

[0035] The top cover 10 includes a cover plate body 11 and an injection area 12 recessed in a first direction X relative to the cover plate body 11, wherein the injection area 12 is provided with a through injection hole 13;

[0036] The sealing pin 20 includes a connecting area 21 and a positioning area 22 recessed in a first direction X relative to the connecting area 21. The connecting area 21 is connected to the cover plate body 11. The positioning area 22 is used to cover the injection hole 13. A portion of the positioning area 22 protrudes in a second direction Y to form a sealing part 221. A mating structure 222 is formed between the sealing part 221 and the edge of the positioning area 22. The mating structure 222 mates with the groove 122 to fix the relative position of the sealing pin 20 and the top cover 10.

[0037] The cover plate body 11 includes a first plate surface 111 and a second plate surface 112 disposed opposite to each other. The first direction X is the direction from the first plate surface 111 to the second plate surface 112, and the first direction X is opposite to the second direction Y.

[0038] Specifically, both the top cover 10 and the sealing nail 20 can 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 10 and the sealing nail 20, and can also ensure the welding yield and welding strength of the sealing nail 20 and the top cover 10.

[0039] The thickness of the sealing stud 20 is less than the thickness of the top cover 10 to reduce the weight load exerted by the sealing stud 20 on the top cover 10. Specifically, the thickness of the top cover 10 ranges from 0.30 to 3.0 mm, and more preferably, the thickness of the top cover 10 ranges from 0.5 to 0.8 mm. The thickness of the sealing stud 20 ranges from 0.1 to 2 mm, and more preferably, the thickness of the sealing stud 20 ranges from 0.2 to 0.5 mm.

[0040] In this design, the connection area 21 of the sealing pin 20 is welded and fixed to the cover plate body 11 surrounding the liquid injection hole 13 of the top cover 10. To ensure welding strength, the width of the connection area 21 must be at least 0.8-2mm, and the connection area 21 must not be too close to the liquid injection hole 13 to avoid welding spatter entering the liquid injection hole 13 and contaminating the electrolyte inside the cell casing. Therefore, when both the sealing pin 20 and the liquid injection hole 13 are circular, the diameter of the sealing pin 20 can be set to 3-4 times the diameter of the liquid injection hole 13. This ensures that the connection area 21 located at the edge of the sealing pin 20 is as far away from the liquid injection hole 13 as possible, and also ensures the connection width between the connection area 21 and the cover plate body 11. This ensures both the welding strength between the top cover 10 and the sealing pin 20 and prevents welding spatter from entering the liquid injection hole 13 and contaminating the electrolyte inside the cell casing, thus affecting the welding effect. Specifically, the diameter of the sealing pin 20 ranges from 8-12mm, and the diameter of the liquid injection hole 13 ranges from 2-4mm.

[0041] The first plate surface 111 and the second plate surface 112 are two opposite surfaces on the cover plate body 11. The cover plate body 11 is used to cooperate with the outer shell 02 to form a receiving space for accommodating bare battery cells. The second plate surface 112 is the side closer to the bare battery cells, and the first plate surface 111 is the side away from the bare battery cells, that is, the outer surface of the cover plate body 11.

[0042] The top cover 10 includes a cover plate body 11, a groove 122, and a protrusion 121 arranged around it. The sealing nail 20 includes a connecting area 21, a mating structure 222, and a sealing part 221 arranged around it. The sealing nail 20 is stacked with the top cover 10. The sealing nail 20 is located on the side of the top cover 10 away from the bare battery cell (i.e., on the side of the first plate surface 111). The connecting area 21 is correspondingly arranged with the cover plate body 11. The mating structure 222 is correspondingly arranged with the groove 122. The sealing part 221 is correspondingly arranged with the protrusion 121. The connecting area 21 is connected to the cover plate body 11. This connection can be laser welding.

[0043] The connecting area 21 is arranged around the mating structure 222, the mating structure 222 is arranged around the sealing part 221, the cover plate body 11 is arranged around the groove 122, and the groove 122 is arranged around the protrusion 121. Therefore, the connection between the connecting area 21 and the cover plate body 11 can make the connection between the sealing nail 20 and the top cover 10 fixed and sealed.

[0044] The engagement between the mating structure 222 and the groove 122 enables the sealing nail 20 to be initially positioned with the top cover 10. Based on this, the connection area 21 is connected to the cover plate body 11, which can significantly improve the connection efficiency and thus improve the sealing efficiency of the sealing nail 20 on the injection hole 13.

[0045] In this embodiment, an injection area 12 recessed in the first direction X is provided on the cover plate body 11 of the top cover 10, and an injection hole 13 is provided on the injection area 12. The connecting area 21 of the sealing nail 20 is connected to the cover plate body 11, and a positioning area 22 recessed in the first direction X is provided on the connecting area 21 of the sealing nail 20. A portion of the positioning area 22 protrudes in the second direction Y to form a sealing part 221. A mating structure 222 is formed between the sealing part 221 and the edge of the connecting area 21. The mating structure 222 mates with the injection area 12, so that the relative position of the sealing nail 20 and the top cover 10 is fixed, thereby achieving rapid positioning of the top cover 10 and the sealing nail 20 and improving the welding efficiency of the sealing nail 20 and the top cover 10. Furthermore, the sealing effect of the sealing pin 20 on the injection hole 13 on the top cover 10 is achieved by welding the connecting area 21 of the sealing pin 20 to the cover body 11. During the welding process, the corresponding area on the connecting area 21 and the cover body 11 is the welding area. The mating structure 222 is located between the welding area and the sealing part 221, which facilitates the quick determination of the welding area and further improves welding efficiency. Moreover, the setting of the sealing part 221 on the sealing pin 20 can reduce the opening size of the positioning area 22, thereby reducing the pit on the outer surface of the sealing pin 20, which is beneficial to improving the flatness of the outer surface of the cover assembly 01.

[0046] In some embodiments, such as Figure 3 and Figure 4 As shown, a portion of the injection area 12 protrudes in the second direction to form a protrusion 121, and a groove 122 is formed between the protrusion 121 and the edge of the injection area 12. The mating structure 222 is mated with the groove 122 to fix the relative position of the sealing nail 20 and the top cover 10.

[0047] Specifically, the groove 122 is located between the protrusion 121 and the cover plate body 11, and the mating structure 222 is located between the sealing part 221 and the connecting area 21. The protrusion 121 is correspondingly arranged with the sealing part 221, and the connecting area 21 is correspondingly arranged with the cover plate body 11, so that the groove 122 corresponds to the mating structure 222. The mating structure 222 is located in the groove 122 and, through mating with the groove 122, fixes the relative position of the sealing nail 20 and the top cover 10. The setting of the groove 122 enhances the mating effect between the mating structure 222 and the injection area 12, thereby enhancing the stability of the rapid positioning effect of the sealing nail 20 and the top cover 10, further facilitating the welding of the connecting area 21 and the cover plate body 11, and improving the welding efficiency of the sealing nail 20 and the top cover 10.

[0048] In some embodiments, both the groove 122 and the mating structure 222 are annular structures.

[0049] Specifically, the mating structure 222 is arranged around the sealing part 221, and the groove 122 is arranged around the protrusion 121. The groove 122 and the mating structure 222 are annular structures, which can increase the mating range of the groove 122 and the mating structure 222, thereby enhancing the mating effect of the groove 122 and the mating structure 222. This is beneficial to the positioning stability of the sealing nail 20 and the top cover 10, and thus helps to improve welding efficiency.

[0050] In some embodiments, such as Figure 3 and Figure 4 As shown, the injection hole 13 is located on the protrusion 121, and the sealing part 221 is used to cover the injection hole 13.

[0051] Specifically, the groove 122 is located between the cover plate body 11 and the protrusion 121. The groove 122 separates the welding area on the cover plate body 11 (i.e., the area where the cover plate body 11 is welded to the connection area 21) from the protrusion 121. The injection hole 13 is set on the protrusion 121, which enables the groove 122 to separate the welding area and the injection hole 13, effectively preventing welding spatter from the welding area from entering the injection hole 13 and ensuring the welding effect.

[0052] In some embodiments, such as Figure 3 As shown, the axial section of both the mating structure 222 and the groove 122 is a ︺-shaped structure.

[0053] Specifically, the axial cross-sections of the mating structure 222 and the groove 122 are both ︺-shaped structures, so as to realize the snap-fit ​​between the mating structure 222 and the groove 122 through the ︺-shaped structure, thereby realizing the rapid positioning of the sealing nail 20 and the top cover 10.

[0054] In this embodiment, the axial section of both the mating structure 222 and the groove 122 is a ︺-shaped structure. The outer periphery of the mating structure 222 is fully adapted to the inner wall of the groove 122. When the mating structure 222 is engaged with the groove 122, the position of the sealing pin 20 relative to the top cover 10 is fixed, which helps to improve the connection stability between the sealing pin 20 and the top cover 10, thereby improving the welding efficiency between the sealing pin 20 and the top cover 10 and increasing the assembly efficiency of the sealing pin 20 on the top cover 10.

[0055] In some embodiments, the height of the side of the sealing portion 221 away from the protrusion 121 in the second direction Y is equal to or higher than the height of the side of the connecting area 21 away from the cover plate body 11.

[0056] Specifically, both the mating structure 222 and the groove 122 have a ︺-shaped axial section. An external force parallel to the moving direction of the mating structure 222 needs to be applied to assist the mating structure 222 in entering the groove 122 and engaging with the groove 122, thereby achieving rapid positioning of the sealing nail 20 on the top cover 10.

[0057] The height of the side of the sealing part 221 away from the protrusion 121 in the second direction Y is equal to or higher than the height of the side of the connecting area 21 away from the cover plate body 11. That is, the sealing part 221 is provided at the same height or protruding from the connecting area 21 on the outer surface of the cover plate assembly 01. In other words, the sealing part 221 is not recessed relative to the connecting area 21. This ensures that when the sealing nail 20 and the top cover 10 are initially positioned, external force can be applied to the connecting area 21 and the sealing part 221 of the sealing nail 20 at the same time to promote the engagement of the mating structure 222 of the U-shaped structure with the groove 122.

[0058] In addition, during the use of the battery cell, the sealing part 221 of the sealing nail 20 and the connection area 21 are at the same height, or the height of the sealing part 221 is slightly greater than the height of the connection area 21, so as to avoid large pits appearing on the surface of the cover assembly 01 away from the bare battery cell, which would affect the ability of the cover assembly 01 to resist external forces.

[0059] In some embodiments, such as Figure 4 As shown, the axial section of the mating structure 222 is a V-shaped structure, and the axial section of the groove 122 is a ︺-shaped structure.

[0060] Specifically, the axial section of the groove 122 is a ︺-shaped structure, and the axial section of the mating structure 222 is a V-shaped structure. The V-shaped structure is located inside the ︺-shaped structure and engages with the ︺-shaped structure, which enables the mating structure 222 to quickly engage with the groove 122, thereby completing the rapid positioning of the sealing nail 20 on the top cover 10 and further improving the welding efficiency and assembly efficiency of the sealing nail 20 and the top cover 10.

[0061] In some embodiments, the height of the side of the sealing portion 221 away from the protrusion 121 in the second direction Y is lower than the height of the side of the connecting area 21 away from the cover plate body 11.

[0062] Specifically, the connecting area 21 is connected to the cover plate body 11, and the external pressure on the connecting area 21 is transmitted to the cover plate body 11. The sealing part 221 covers the injection hole 13, but it is not connected to the protrusion 121 where the injection hole 13 is located. The external pressure on the sealing part 221 is transmitted to the mating structure 222 connected to it, and then transmitted from the mating structure 222 to the groove 122.

[0063] The height of the side of the sealing portion 221 away from the protrusion 121 in the second direction Y is lower than the height of the side of the connecting area 21 away from the cover plate body 11. That is, the sealing portion 221 is recessed relative to the connecting area 21 on the outer surface of the cover plate body 11, so that the connecting area 21 protects the sealing portion 221, preventing the sealing portion 221 from being subjected to external pressure. This prevents the sealing portion 221 from transmitting pressure to the tip of the V-shaped structure of the mating structure 222 when subjected to pressure, thus avoiding wear on the groove 122 and causing electrolyte leakage.

[0064] In this embodiment, the sealing part 221 is recessed on the outer surface of the cover plate body 11, which can reduce the wear of the V-shaped tip of the mating structure 222 on the groove 122, thereby improving the service life of the groove 122 and the cover plate assembly 01.

[0065] In some embodiments, the protrusion 121 is located in the bottom center region of the injection area 12, and the sealing portion 221 is located in the bottom center region of the positioning area 22.

[0066] Specifically, the protrusion 121 is located in the central region of the injection area 12, and the sealing part 221 is located in the central region of the positioning area 22, so that the protrusion 121 and the sealing part 221 are respectively located in the central region of their respective positions. The connecting area 21 and the mating structure 222 are evenly arranged around the sealing part 221, and the groove 122 is evenly arranged around the protrusion 121. This facilitates the engagement of the mating structure 222 with the groove 122, while also ensuring that the sealing pin 20 evenly seals the injection hole 13 around the injection hole 13, thereby improving the welding effect of the sealing pin 20 and the top cover 10.

[0067] In some embodiments, the height of the cover body 11 in the second direction Y is higher than that of the protrusion 121.

[0068] Specifically, the height of the protrusion 121 is set lower than the height of the cover plate body 11 to avoid the injection hole 13 protruding relative to the cover plate body 11, thus preventing the protrusion 121 (especially the injection hole 13 on the protrusion 121) from being directly impacted by external forces and causing electrolyte leakage. This helps to protect the injection hole 13 and improves the practicality of the cover plate assembly 01.

[0069] In some embodiments, the recess depth of the injection area 12 relative to the cover plate body 11 in the first direction X is 0.2 to 5 mm;

[0070] The protrusion height of the protrusion 121 relative to the injection area 12 in the second direction Y is 0.1 to 2 mm;

[0071] The width of the connection area 21 is 0.8 to 2 mm.

[0072] Specifically, the depth of the injection area 12 in the first direction X relative to the cover plate body 11 is the depth of the groove 122 relative to the cover plate body 11; the height of the protrusion 121 in the second direction Y relative to the injection area 12 is the height of the protrusion 121 relative to the inner bottom wall of the groove 122; the mating structure 222 of the sealing nail 20 engages with the groove 122; the protrusion 121 and the cover plate body 11 are located on opposite sides of the groove 122. Therefore, the depth of the groove 122 relative to the cover plate body 11 and the height of the protrusion 121 relative to the inner bottom wall of the groove 122 are related to the engaging effect of the mating structure 222 with the groove 122. The depth of the injection area is 0.2–5 mm, and the height of the protrusion is 0.1–2 mm, which ensures the engaging effect of the mating structure 222 with the groove 122 and enables rapid positioning of the sealing nail 20 and the top cover 10.

[0073] For example, the top cover 10 includes the cover plate body 11 and an injection area 12 that is recessed 3 mm in the first direction X relative to the cover plate body 11, and a portion of the bottom of the injection area 12 protrudes 2 mm in the second direction Y to form a protrusion 121.

[0074] Specifically, the connecting area 21 is used to connect with the cover plate body 11. The connecting area 21 is arranged around the positioning area 22. Therefore, the width of the connecting area 21 is closely related to the connection strength between the sealing nail 20 and the top cover 10 and the sealing effect of the sealing nail 20 on the injection hole 13. The width of the connecting area 21 is set to 0.8 to 2 mm to accommodate top covers 10 of different sizes, avoid the connecting area 21 occupying too large an area, and affect the normal application of the cover plate assembly 01. At the same time, the connection strength between the sealing nail 20 and the top cover 10 is guaranteed.

[0075] For example, the width of the connection area 21 of the sealing nail 20 is set to 2 mm.

[0076] In some embodiments, a clearance 30 is provided between the sealing portion 221 and the protrusion 121, and the distance of the clearance 30 is 0.1 to 3 mm.

[0077] Specifically, the clearance 30 can prevent the sealing part 221 from contacting the protrusion 121, thereby reducing the assembly time of the sealing nail 20 on the top cover 10, which is conducive to improving the assembly efficiency and welding efficiency of the sealing nail 20 on the top cover 10, and is beneficial to its widespread application.

[0078] For example, the distance of the clearance 30 is 2 mm.

[0079] In some embodiments, the connection area 21 near the cover plate body 1111 has a chamfer at the connection with the mating structure 222, the radius of which is 0.05 to 5 mm, and more preferably 0.5 to 2 mm. Correspondingly, the connection area 11 near the connection area 21 has a chamfer at the connection with the injection area 12, the radius of which is 0.05 to 5 mm, and more preferably 0.5 to 2 mm.

[0080] In some embodiments, the axial section of both the groove 122 and the mating structure 222 is a ︺-shaped structure. The bottom surface of the groove 122 and the bend of the side surface of the groove 122 have a chamfer, the radius of which is 0.05 to 5 mm, and more preferably 0.5 to 2 mm. Correspondingly, the bottom surface of the mating structure 222 and the bend of the side surface of the mating structure 222 have a chamfer, the radius of which is 0.05 to 5 mm, and more preferably 0.5 to 2 mm.

[0081] In some embodiments, the connection between the groove 122 and the protrusion 121 has a chamfer with a radius of 0.05 to 10 mm. Correspondingly, the connection between the mating structure 222 and the sealing part 221 has a chamfer with a radius of 0.05 to 10 mm.

[0082] The chamfering design makes the different structures on the top cover 10 and the sealing nail 20 connected by an arc, which can avoid stress concentration at the connection of adjacent structures and prevent the connection from breaking. This helps to improve the strength of the top cover 10 and the sealing nail 20.

[0083] In some embodiments, such as Figure 5 and Figure 6 As shown, the angle γ between the bottom of the groove 122 and its side is smaller than the angle α between the bottom of the mating structure 222 and its side, that is, the slope of the side of the groove 122 is greater than the slope of the side of the mating structure 222, which is beneficial to the mating effect of the mating structure 222 and the groove, and thus beneficial to the positioning stability of the sealing nail 20 and the top cover 10.

[0084] In some embodiments, the roughness of the side of the connection area 21 away from the cover plate body 11 is greater than or equal to 0.4 μm. It should be noted that the welding of the sealing nail 20 to the cover plate body 11 typically uses laser welding. During laser welding, if the surface of the sealing nail 20 (especially the surface of the connection area 21) 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 even some of the reflected light can 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 surface roughness of the connection area 21 can be increased. This surface roughness can be achieved through grinding, embossing, passivation, matte finishing, etc., to avoid the high reflection phenomenon during the welding of the sealing nail 20 to the cover plate body 11.

[0085] Based on the same inventive concept, this application also provides a battery cell, such as... Figure 1 As shown, it includes:

[0086] Cover assembly 01 as described above;

[0087] The outer casing 02, the cover plate assembly 01 is connected to the outer casing 02 and forms a receiving space, and the liquid injection hole 13 is connected to the receiving space.

[0088] The beneficial effects of the battery cell are the same as those of the cover plate assembly 01 described above, and will not be repeated here.

[0089] 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 utility model, 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 utility model as described above, which are not provided in the details for the sake of brevity.

[0090] 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 being provided with a through injection hole; A sealing pin includes a connecting area and a positioning area recessed in a first direction relative to the connecting area. The connecting area is connected to the cover plate body, and the positioning area is used to cover the injection hole. A portion of the positioning area protrudes in a second direction to form a sealing part. A mating structure is formed between the sealing part and the edge of the positioning area. The mating structure mates with the injection area to fix the relative position of the sealing pin and the top cover. 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, and the first direction is opposite to the second direction.

2. The cover plate assembly according to claim 1, characterized in that, A portion of the injection area protrudes in the second direction to form a protrusion, and a groove is formed between the protrusion and the edge of the injection area. The mating structure mates with the groove to fix the relative positions of the sealing pin and the top cover.

3. The cover plate assembly according to claim 2, characterized in that, Both the groove and the mating structure are annular structures.

4. The cover plate assembly according to claim 2, characterized in that, The injection hole is located on the protrusion, and the sealing part is used to cover the injection hole.

5. The cover plate assembly according to claim 2, characterized in that, Both the mating structure and the groove have a ︺-shaped axial section.

6. The cover plate assembly according to claim 5, characterized in that, The height of the side of the sealing portion away from the protrusion in the second direction is equal to or higher than the height of the side of the connecting area away from the cover plate body.

7. The cover plate assembly according to claim 2, characterized in that, The axial section of the mating structure is V-shaped, and the axial section of the groove is ︺-shaped.

8. The cover plate assembly according to claim 7, characterized in that, The height of the side of the sealing portion away from the protrusion in the second direction is lower than the height of the side of the connecting area away from the cover plate body.

9. The cover plate assembly according to claim 1, characterized in that, The height of the cover plate body in the second direction is higher than that of the protrusion.

10. A battery cell, characterized in that, include: The cover plate assembly as described in any one of claims 1 to 9; 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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