Cover plate assembly and battery cell

Abstract

The utility model provides a cover plate assembly and a battery cell, and the cover plate assembly comprises a top cover which comprises a cover plate main body and a liquid injection area which is recessed towards a first direction relative to the cover plate main body, and the liquid injection area is provided with a 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 located in the liquid injection area and matched with the liquid injection area, and the positioning area is used for covering the liquid injection hole. The sealing nail comprises the positioning area which is sunken in the first direction relative to the connecting area, the positioning area is connected with the liquid injection area in a clamped mode, and rapid positioning of the top cover and the sealing nail is achieved through cooperation of the positioning area and the liquid injection area, so that the welding 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 a liquid injection hole. The top cover needs to be fixed to the liquid injection hole by welding with the sealing nail to achieve the seal. However, the welding efficiency between the sealing nail and the top cover needs 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, wherein the injection area is provided with an injection hole;

[0006] The sealing pin includes a connecting area and a positioning area recessed in the first direction relative to the connecting area. The connecting area is connected to the cover plate body, and the positioning area is located in the injection area and cooperates with the injection area to fix the relative position of the positioning area and the injection area. The positioning area is 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, wherein the first direction is the direction in which the first plate surface faces the second plate surface.

[0008] Furthermore, a portion of the positioning area is recessed in the first direction to form a positioning part, which is located inside the injection hole and is fixed relative to the injection hole.

[0009] Furthermore, the positioning part protrudes relative to the injection area in a first direction.

[0010] Furthermore, the second plate surface is provided with an circumferential groove that is recessed in a second direction, and the circumferential groove is arranged around the injection area;

[0011] The second direction is opposite to the first direction.

[0012] 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.

[0013] The positioning 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.

[0014] 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°.

[0015] Furthermore, the positioning part includes a positioning section and a horizontal section connected to each other, the horizontal section being parallel to the first recess; a third included angle is formed between the inner wall of the injection hole and the extending direction of the first recess, and a fourth included angle is formed between the positioning section and the horizontal section, the third included angle being smaller than the fourth included angle, and the fourth included angle being greater than 90°.

[0016] Furthermore, the distance between the side of the horizontal segment away from the connecting area and the side of the second recess away from the connecting area is the first distance, and the distance between the side of the second recess away from the connecting area and the side of the connecting area close to the cover plate body is the second distance, and the first distance is greater than the second distance.

[0017] Furthermore, the thickness of the connection area is less than or equal to the thickness of the positioning area.

[0018] Furthermore, the width of the overlapping area between the connecting area and the main body of the cover plate is 0.8-2 mm.

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

[0020] The cover plate assembly as described in any of the preceding items;

[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 sealing pin includes a positioning area recessed in the first direction relative to the connecting area. The positioning area engages with the liquid injection area. The cooperation between the positioning area and the liquid injection area enables 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 cooperation between the positioning area and the liquid injection area adds another layer of sealing on top of the welding seal between the top cover and the sealing pin, which can effectively improve the sealing effect of the sealing pin on the liquid injection hole of 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 of this utility model;

[0025] Figure 2 This is a top view of the battery cell of this utility model.

[0026] Figure 3 for Figure 2 Schematic diagram of a partial cross-section along the AA direction. Figure 1 ;

[0027] Figure 4 for Figure 2 Schematic diagram of a partial cross-section along the AA direction. Figure 2 ;

[0028] Figure 5 for Figure 2 Partial cross-sectional view of the top cover in the AA direction. Figure 1 ;

[0029] Figure 6 for Figure 2 Schematic diagram of the sealing pin in the AA direction Figure 1 ;

[0030] Figure 7 for Figure 2 Partial cross-sectional view of the top cover in the AA direction. Figure 2 ;

[0031] Figure 8 for Figure 2 Schematic diagram of the sealing pin in the AA direction Figure 2 ;

[0032] In the above diagram, the X-arrow indicates the first direction, and the Y-arrow indicates the second direction;

[0033] In the figure, 001 is the cover plate assembly; 002 is the outer shell; 100 is the top cover; 110 is the cover plate body; 111 is the first plate surface; 112 is the second plate surface; 120 is the injection area; 121 is the first transition part; 122 is the first recessed part; 123 is the injection hole; 130 is the circumferential groove; 200 is the sealing pin; 210 is the connecting area; 220 is the positioning area; 221 is the second transition part; 222 is the second recessed part; 223 is the positioning part; 223a is the positioning section; 223b is the horizontal section; and 300 is the clearance. Detailed Implementation

[0034] 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.

[0035] 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.

[0036] The following describes specific embodiments in conjunction with... Figures 1-8 The technical solution of this application will be described in detail below.

[0037] In view of this, such as Figure 1 , Figure 2 , Figure 3 As shown, in some embodiments, a cover plate assembly 001 includes:

[0038] The top cover 100 includes a cover plate body 110 and an injection area 120 recessed in a first direction relative to the cover plate body 110, wherein the injection area 120 is provided with an injection hole 123;

[0039] The sealing pin 200 includes a connecting area 210 and a positioning area 220 recessed in the first direction relative to the connecting area 210. The connecting area 210 is connected to the cover plate body 110, and the positioning area 220 cooperates with the injection area 120 to fix the relative positions of the positioning area 220 and the injection area 120. The positioning area 220 is used to cover the injection hole 123.

[0040] The cover plate body 110 includes a first plate surface 111 and a second plate surface 112 disposed opposite to each other, wherein the first direction is the direction from the first plate surface 111 toward the second plate surface 112, that is... Figure 3 The X direction in the equation.

[0041] 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] 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. Specifically, the thickness of the top cover 100 ranges from 0.30 to 3.0 mm, and more preferably, the thickness of the top cover 100 ranges from 0.5 to 0.8 mm. The thickness of the sealing stud 200 ranges from 0.1 to 2 mm, and more preferably, the thickness of the sealing stud 200 ranges from 0.2 to 0.5 mm.

[0043] The connecting area 210 of the sealing nail 200 is welded and fixed to the cover plate body 110 surrounding the injection hole 123 of the top cover 100. To ensure the welding strength, such as Figure 3 As shown, the overlapping portion of the connection area 210 and the cover plate body 110 is the welding area. Its width L1 must be at least 0.8-2mm, and this welding area should not be too close to the injection hole 123 to avoid welding spatter entering the injection hole 123 and contaminating the electrolyte in the cell casing. Therefore, when both the sealing pin 200 and the injection hole 123 are circular, the diameter of the sealing pin 200 can be set to 3-4 times the diameter of the injection hole 123 to ensure that the welding area located at the edge of the sealing pin 200 is as far away from the injection hole 123 as possible, and to ensure the connection width between the connection area 210 and the cover plate body 110. This ensures both the welding strength between the top cover 100 and the sealing pin 200 and prevents welding spatter from entering the injection hole 123 and contaminating the electrolyte in the cell casing 002, thus affecting the welding effect. Specifically, the diameter of the sealing pin 200 is in the range of 8-12mm; the diameter of the injection hole 123 is in the range of 2-4mm.

[0044] The positioning area 220 cooperates with the injection area 120, specifically in that the positioning area 220 is located within the injection area 120, and this cooperation can be a snap-fit ​​or abutment-fit, so that the relative positions of the positioning area 220 and the injection area 120 are fixed.

[0045] In this embodiment, the cover plate body 110 of the top cover 100 is provided with an injection area 120 recessed in a first direction. The sealing nail 200 includes a positioning area 220 recessed in the first direction relative to the connecting area 210. The positioning area 220 engages with the injection area 120. The cooperation between the positioning area 220 and the injection area 120 enables rapid positioning of the top cover 100 and the sealing nail 200, thereby improving the welding efficiency of the sealing nail 200 and the top cover 100. In addition, the cooperation between the positioning area 220 and the injection area 120 adds another layer of sealing on top of the welded seal between the top cover 100 and the sealing nail 200, which can effectively improve the sealing effect of the sealing nail 200 on the injection hole 123 of the top cover 100.

[0046] In some embodiments, such as Figure 4 As shown, a portion of the positioning area 220 is recessed in the first direction to form a positioning part 223. The positioning part 223 is located within the injection hole 123 and is fixed in position relative to the injection hole 123. Specifically, the positioning part 223 protrudes from the injection area 120 in the first direction.

[0047] In this embodiment, a positioning part 223 is punched out of the injection area 120 of the sealing nail 200. This positioning part 223 enters the injection hole 123, and its outer diameter matches the diameter of the injection hole 123. This allows for better positioning and correction of the sealing nail 200 by the injection hole 123, resulting in more precise welding positioning of the sealing nail 200 and the top cover 100. Furthermore, the positioning part 223 protrudes from the injection area 120 in the first direction, ensuring sufficient length for better positioning and correction. Additionally, the injection hole 123 of the top cover 100 has relatively weak strength. The positioning part 223, located within the injection hole 123 and protruding from the injection area 120, strengthens the top cover 100 at the injection port and prevents welding spatter from contaminating the electrolyte through the injection hole 123, thus improving the battery cell's lifespan.

[0048] In some embodiments, such as Figure 3 , Figure 4 As shown, the second plate surface 112 is provided with a direction towards the second direction (i.e. Figure 3 , Figure 4A circumferential groove 130 (in the Y direction) is recessed around the injection area 120, wherein the second direction is opposite to the first direction. Because the injection area 120 is recessed relative to the cover body 110 in the first direction, a large bending stress is easily generated between the cover body 110 and the injection area 120. The circumferential groove 130 releases this bending stress, thereby ensuring the strength and stability of the top cover 100.

[0049] In some embodiments, such as Figure 5 , Figure 6 As shown, the injection area 120 includes a first transition portion 121 and a first recessed portion 122 connected to each other. The first recessed portion 122 is parallel to the cover plate body 110. The injection hole 123 is located on the first recessed portion 122. The first transition portion 121 is connected to the cover plate body 110. A first included angle α is formed between the first transition portion 121 and the first recessed portion 122.

[0050] The positioning area 220 includes a second transition portion 221 and a second recessed portion 222 connected to each other. The second recessed portion 222 is parallel to the cover plate body 110 and is used to cover the injection hole 123. The second transition portion 221 is connected to the connecting area 210. A second included angle β is formed between the second transition portion 221 and the second recessed portion 222.

[0051] Wherein, a clearance gap 300 is provided between the first recess 122 and the second recess 222, such as Figure 4 As shown, the clearance 300 is 0.5–1 mm; Figure 5 , Figure 6 As shown, a first included angle α is formed between the first transition portion 121 and the first recessed portion 122, and a second included angle β is formed between the second transition portion 221 and the second recessed portion 222. The first included angle α is smaller than the second included angle β. This clearance 300 and the fact that the first included angle α is smaller than the second included angle β provide 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.

[0052] In addition, such as Figure 5 , Figure 6As shown, 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 122 relative to the first transition portion 121 and the second recessed portion 222 relative to the second transition portion 221 are relatively large. This effectively reduces the bending stress between the first transition portion 121 and the first recessed portion 122, as well as between the second transition portion 221 and the second recessed portion 222. Furthermore, 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 positioning 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 positioning 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.

[0053] In some embodiments, such as Figure 7 , Figure 8 As shown, the positioning part 223 includes a positioning section 223a and a horizontal section 223b connected to each other. The horizontal section 223b is parallel to the first recess 122. A third included angle θ is formed between the inner wall of the injection hole 123 and the extending direction of the first recess 122, and a fourth included angle γ is formed between the positioning section 223a and the horizontal section 223b. The third included angle θ is smaller than the fourth included angle γ. This setting, where the third included angle θ is smaller than the fourth included angle γ, 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. Additionally, as... Figure 8 As shown, the fourth included angle γ is greater than 90°, indicating that its corresponding angle γ' (i.e., the concave angle of the positioning part 223 relative to the second concave part 222) is also greater than 90°, and γ' is also greater than θ, that is, the concave angle is relatively large, which makes the bending stress between the second concave part 222 and the positioning part 223 and the bending stress between the positioning section 223a and the horizontal section 223b smaller, thereby better maintaining the overall strength of the sealing nail 200.

[0054] In some embodiments, such as Figure 6As shown, the distance between the side of the horizontal segment 223b away from the connecting area 210 and the side of the second recess 222 away from the connecting area 210 is the first distance H1, and the distance between the side of the second recess 222 away from the connecting area 210 and the side of the connecting area 210 closer to the cover plate body 110 is the second distance H2. The first distance H1 is greater than the second distance H2. The first distance H1 is the height of the positioning part 223, and the second distance H2 is the depth of the recess of the positioning area 220 relative to the connecting area 210. Generally, due to limitations imposed by other structures (such as insulating components) of the cover plate assembly 001, the recess depth of the positioning area 220 is relatively shallow. This results in poor stability of the positioning of the positioning area 220 and the injection area 120. Therefore, in this embodiment, the positioning part 223 is set high enough that its height is greater than the recess depth of the positioning area 220. This makes the snap-fit ​​positioning between the positioning part 223 and the injection hole 123 more stable, which helps to improve the welding efficiency of the sealing nail 200 and the top cover 100.

[0055] In some embodiments, such as Figure 3 As shown, the thickness of the connecting area 210 is less than or equal to the thickness of the positioning area 220. Specifically, the thickness of the positioning area 220 ranges from 0.2 to 0.5 mm, and the thickness of the connecting area 210 ranges from 0.1 to 0.3 mm.

[0056] The overlapping portion of the connecting area 210 and the cover plate body 110 is the welding area where the sealing nail 200 is welded to the top cover 100. The thickness of this welding area should not be too thick. If it is too thick, heat will not dissipate easily during welding, leading to excessive heat accumulation and causing the connecting area 210 or areas near it to warp. Therefore, in this embodiment, the thickness of the connecting area 210 can be less than the thickness of the positioning area 220. While reducing weight, a thinner connecting area 210 allows for easier heat dissipation during welding, helping to reduce warping of the sealing nail 200 caused by heat concentration. Simultaneously, a thinner connecting area 210 results in less deformation after heating, better maintaining the shape and dimensional stability of the sealing nail 200. Furthermore, when thinning the connecting area 210, it is necessary to ensure its strength and rigidity meet usage requirements to avoid deformation or damage to the steel nail during use due to excessive thinning. Therefore, when the thickness of the sealing nail 200 is already sufficiently thin, the thickness of the connecting area 210 in this embodiment can also be equal to the thickness of the positioning area 220.

[0057] In this embodiment, the thickness of the connecting area 210 is less than or equal to the thickness of the positioning area 220, which means that the connecting area 210 is thin enough. The thinner connecting area 210 allows heat to dissipate more easily during the welding process, which helps to reduce the phenomenon of the sealing nail 200 lifting due to heat concentration.

[0058] 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 surface roughness 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.

[0059] 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.

[0060] 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, wherein the injection area is provided with an injection hole; The sealing pin includes a connecting area and a positioning area recessed in the first direction relative to the connecting area. The connecting area is connected to the cover plate body, and the positioning area cooperates with the injection area to fix the relative position of the positioning area and the injection area. The positioning area is used to cover the injection hole. The cover plate body includes a first plate surface and a second plate surface arranged opposite to each other, wherein the first direction is the direction in which the first plate surface faces the second plate surface.

2. The cover plate assembly according to claim 1, characterized in that, A portion of the positioning area is recessed in the first direction to form a positioning part, which is located inside the injection hole and is fixed in position relative to the injection hole.

3. The cover plate assembly according to claim 2, characterized in that, The positioning part protrudes relative to the injection area in a first direction.

4. The cover plate assembly according to claim 1, characterized in that, The second plate surface is provided with an circumferential groove that is recessed in a second direction, and the circumferential groove is arranged around the injection area; The second direction is opposite to the first direction.

5. The cover plate assembly according to claim 2, characterized in that, The injection area includes a first transition portion and a first recess portion connected to each other. The first recess portion is parallel to the cover plate body, and the injection hole is located on the first recess 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 recess portion. The positioning 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. 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°.

6. The cover plate assembly according to claim 5, characterized in that, The positioning part includes a positioning section and a horizontal section connected to each other. The horizontal section is parallel to the first recess. The inner wall of the injection hole forms a third angle with the extending direction of the first recess. The positioning section and the horizontal section form a fourth angle. The third angle is smaller than the fourth angle, and the fourth angle is greater than 90°.

7. The cover plate assembly according to claim 6, characterized in that, The distance between the side of the horizontal segment away from the connecting area and the side of the second recess away from the connecting area is the first distance, and the distance between the side of the second recess away from the connecting area and the side of the connecting area close to the cover plate body is the second distance. The first distance is greater than the second distance.

8. The cover plate assembly according to claim 1, characterized in that, The thickness of the connection area is less than or equal to the thickness of the positioning area.

9. The cover plate assembly according to claim 1, characterized in that, The width of the overlapping area between the connecting area and the main body of the cover plate is 0.8-2 mm.

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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