A battery top cover adhesive structure

Abstract

This utility model relates to the field of battery cell manufacturing technology and discloses a battery top cover adhesive structure, including a conductive component with a first surface and a second surface arranged opposite to each other. The conductive component includes a core, a negative electrode tab, and a negative electrode connecting piece. A first adhesive component is attached to the first surface, covering the negative electrode connecting piece and extending to the core area on both adjacent sides. A cover plate covers the first adhesive component and is welded to the negative electrode connecting piece. A second adhesive component is attached to the second surface, covering the negative electrode connecting piece and extending to the adjacent core area, and covering at least part of the cover plate. This utility model forms an all-around sealed structure by having the first and second adhesive components attached from both sides of the conductive component, both covering the negative electrode connecting piece and extending to the core area. This fills the gaps in the solder joints and the tiny gaps at the corners of the connecting piece, preventing the electrolyte from contacting the negative electrode connecting piece during electrolyte injection, thus avoiding corrosion of the negative electrode connecting piece.

Description

Technical Field

[0001] This utility model relates to the field of battery cell manufacturing technology, and in particular to a battery top cover adhesive bonding structure. Background Technology

[0002] In the production process of lithium batteries, adhesive application is one of the key steps in cell production. After the tabs and connecting pieces are ultrasonically welded, and after the cover plate and connecting pieces are welded, adhesive needs to be applied to certain areas of the tabs, connecting pieces, and cores to protect the tabs and solder marks.

[0003] Traditional adhesive tape is primarily used to protect the tabs and solder joints. However, after the tabs and connectors are welded, issues such as raised solder joints and uneven edges can arise. When applying traditional tape, tiny gaps can easily form in the solder joint seams and corners of the connectors. After electrolyte injection, the electrolyte can easily seep through these gaps to the surface of the negative electrode connector. Since the negative electrode is made of copper, the electrolyte will cause a certain degree of corrosion to the negative electrode connector after injection. Furthermore, during the battery's processes such as electrolyte injection, formation, and aging, changes in ambient temperature and slight deformation of the cell can cause the traditionally applied tape to lift or fall off, leaving the negative electrode connector directly exposed to the electrolyte, significantly accelerating the corrosion rate. Utility Model Content

[0004] The purpose of this invention is to provide a battery top cover adhesive structure to solve the problems in the prior art. By optimizing the adhesive structure, the sealing effect on the connecting piece is improved, the corrosion of the negative electrode connecting piece by the electrolyte is avoided, and welding slag is also prevented from entering the gap between the top cover or the cell, thereby improving the yield of the battery.

[0005] This utility model provides a battery top cover adhesive structure, including: A conductive component having a first surface and a second surface arranged opposite to each other, the conductive component including a core, a negative electrode tab and a negative electrode connecting piece, the negative electrode tabs being led out from opposite ends of the two cores respectively, and the two ends of the negative electrode connecting piece being welded to the negative electrode tabs on both sides respectively. The first adhesive assembly is applied to the first surface, and the first adhesive assembly covers the negative electrode connecting piece and extends to the core area on both adjacent sides. A cover plate is used to cover the first adhesive assembly and weld it to the negative electrode connecting piece. The second adhesive assembly is applied to the second surface and corresponds to the position of the first adhesive assembly. The second adhesive assembly covers the negative electrode connecting piece and extends to the adjacent core area, and covers at least part of the cover plate.

[0006] In the battery top cover adhesive structure described above, preferably, the first adhesive assembly includes a first adhesive part and a second adhesive part, the first adhesive part covers the surface of the negative electrode connecting piece, and the second adhesive part is respectively attached to the connection areas of the negative electrode tab and the winding core on both sides.

[0007] In the battery top cover adhesive structure described above, preferably, the second adhesive portion covers the surface of a portion of the first adhesive portion and a portion of the core.

[0008] In the battery top cover adhesive structure described above, preferably, the negative electrode connecting piece is provided with a negative electrode post, and the first adhesive part is provided with a relief groove adapted to the negative electrode post. When the first adhesive part is attached to the negative electrode connecting piece, the negative electrode post passes through the relief groove.

[0009] In the battery top cover adhesive structure described above, preferably, a solder mark is formed at the welding joint between the negative electrode connecting piece and the negative electrode tab, the second adhesive assembly includes a third adhesive part and a fourth adhesive part, the third adhesive part is respectively attached to the connection area between the negative electrode tab and the winding core on both sides, and the third adhesive part at least partially covers the solder mark and the surface of the winding core, and the fourth adhesive part is attached to the surface of the negative electrode connecting piece.

[0010] In the battery top cover adhesive structure described above, preferably, the fourth adhesive portion completely covers the surface of the negative electrode connecting piece, and at least partially covers the third adhesive portion and the cover plate.

[0011] In the battery top cover adhesive structure described above, preferably, the size of the fourth adhesive part is larger than the size of the negative electrode connecting piece, and the projected area of ​​the fourth adhesive part is within the projected area of ​​the cover plate.

[0012] In the battery top cover adhesive structure described above, preferably, the first adhesive component and the second adhesive component are any one of electrolyte-resistant PET adhesive paper, PP adhesive paper, PC adhesive paper, and PVC adhesive paper.

[0013] In the battery top cover adhesive structure described above, preferably, both the first adhesive application component and the second adhesive application component are high-temperature resistant adhesive paper.

[0014] Compared with the prior art, the present invention uses a first adhesive bonding assembly and a second adhesive bonding assembly to bond from both sides of the conductive component, both of which cover the negative electrode connecting piece and extend to the core area. At the same time, the second adhesive bonding assembly also covers part of the cover plate, forming an all-round sealing structure, filling the gaps in the solder joints and the tiny gaps at the corners of the connecting piece, and preventing the electrolyte from contacting the negative electrode connecting piece during liquid injection, thereby preventing the negative electrode connecting piece from being corroded.

[0015] The first adhesive bonding assembly is attached to the first surface of the conductive component before the cover plate is welded. This effectively prevents welding slag from the cover plate welding from falling into the gap and affecting the quality of the battery cell. The double-sided corresponding layout of the first and second adhesive bonding assemblies greatly improves the bonding firmness of the adhesive structure. Even if the battery cell undergoes slight deformation due to temperature fluctuations during processes such as liquid injection, formation, and aging, it can effectively prevent the tape from lifting or falling off, ensuring that the negative electrode connecting piece is in a protected state for a long time.

[0016] In addition, the first and second adhesive application components not only cover the core area of ​​the negative electrode connector, but also extend to part of the core and cover plate, making the coverage area of ​​the adhesive structure more comprehensive and avoiding gaps and blind spots. The first and second adhesive application components only adhere to the area of ​​the negative electrode conductive component, achieving precise protection and reducing material waste. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the first adhesive part provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the second adhesive part provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the third adhesive part provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the fourth adhesive part provided in an embodiment of this utility model.

[0018] Explanation of reference numerals in the attached figures: 10. Conductive component; 11. First surface; 12. Second surface; 13. Core; 14. Negative electrode tab; 15. Negative electrode connector; 16. Negative electrode post; 17. Solder mark; 18. Positive electrode connector; 20. First adhesive part; 21. Avoidance groove; 22. Second adhesive part; 30. Cover plate; 40. Third adhesive application section; 41. Fourth adhesive application section. Detailed Implementation

[0019] The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0020] See Figure 1-4 As shown, this embodiment provides a battery top cover adhesive bonding structure, including a conductive component 10, a first adhesive bonding component, a cover plate 30, and a second adhesive bonding component, wherein: The conductive component 10 has a first surface 11 and a second surface 12 disposed opposite to each other. The conductive component 10 includes a core 13, a negative electrode tab 14, and a negative electrode connecting piece 15. The negative electrode tabs 14 are respectively led out from opposite ends of the cores 13 on both sides. The two ends of the negative electrode connecting piece 15 are respectively welded to the negative electrode tabs 14 on both sides. A first adhesive component is attached to the first surface 11, covering the negative electrode connecting piece 15 and extending to the adjacent core 13 areas on both sides. A cover plate 30 covers the first adhesive component and is welded to the negative electrode connecting piece 15. A second adhesive component is attached to the second surface 12 and corresponds to the position of the first adhesive component. The second adhesive component covers the negative electrode connecting piece 15 and extends to the adjacent core 13 areas, and covers at least part of the cover plate 30.

[0021] In the embodiments provided in this application, the first adhesive assembly and the second adhesive assembly are respectively bonded to the first surface 11 and the second surface 12 of the conductive component 10, and cover the negative electrode connecting piece 15, the negative electrode tab 14, and the connection area with the core 13, forming a double-sided wrap-around protection. This fills the gaps and corners of the traditional adhesive structure, preventing the electrolyte from penetrating into the negative electrode connecting piece 15 during liquid injection, and effectively reducing corrosion. The first adhesive assembly is pasted before the cover plate 30 is welded, which can prevent the welding slag generated by the welding of the cover plate 30 from entering the first surface 11 of the conductive component 10. The second adhesive assembly is pasted after the cover plate 30 is welded, and covers the second surface 12 of the conductive component 10 and part of the cover plate 30, enhancing the bonding stability between the second adhesive assembly and the component, and preventing the electrolyte from corroding the negative electrode connecting piece 15 during liquid injection. The positions of the first adhesive assembly and the second adhesive assembly are corresponding, and the two cooperate with each other, which can effectively prevent the tape from lifting or falling off due to temperature changes or cell deformation during battery liquid injection, formation and other processes.

[0022] See Figure 1 As shown, in this embodiment, the negative electrode connecting piece 15 is made of copper, which is easily corroded, while the positive electrode connecting piece 18 is made of aluminum, which can form a stable oxide layer and is not easily oxidized. Therefore, in this embodiment, adhesive is applied only to the negative electrode conductive component 10 and its surrounding easily corroded areas, resulting in high protection efficiency, saving material costs, reducing the adhesive application area, and shortening the operation time.

[0023] See Figure 1-2As shown, in some embodiments of this application, the first adhesive assembly includes a first adhesive portion 20 and a second adhesive portion 22. The first adhesive portion 20 covers the surface of the negative electrode connecting piece 15, and the second adhesive portion 22 is respectively attached to the connection areas of the negative electrode tabs 14 and the core 13 on both sides. By covering the negative electrode connecting piece 15 with the first adhesive portion 20 and ensuring a tight fit, and by extending the second adhesive portion 22 from the first adhesive portion 20 to the core 13 area, the gaps at the connection points between the negative electrode connecting piece 15 and the negative electrode tabs 14, and between the negative electrode tabs 14 and the core 13 are filled, preventing any seepage gaps. Furthermore, the second adhesive portion 22 is attached to a portion of the first adhesive portion 20, which can provide auxiliary fixation for the first adhesive portion 20, avoiding the risk of detachment that would occur if the first adhesive portion 20 were only attached to the surface of the negative electrode connecting piece 15, and improving the adhesion firmness. The segmented bonding of the first adhesive portion 20 and the second adhesive portion 22 creates a micro-deformation space. This prevents cracking and detachment caused by deformation of the entire adhesive surface when the core 13 undergoes slight expansion and contraction during battery charging and discharging. Furthermore, the segmented design improves the adhesion between the adhesive and the surface, avoiding bubbles and wrinkles that can occur with large-area bonding. Alternatively, the first adhesive portion 20 and the second adhesive portion 22 in the first adhesive assembly can be a single, integrally molded structure, covering the negative electrode connecting piece 15, the two negative electrode tabs 14, and portions of the core 13 on both sides. However, a tight fit must be ensured to avoid gaps.

[0024] See Figure 2 As shown, in this embodiment, the second adhesive portion 22 covers a portion of the surface of the first adhesive portion 20 and a portion of the core 13. When the first surface 11 of the conductive component 10 is adhered, the second adhesive portion 22 partially covers the first adhesive portion 20. The first adhesive portion 20 provides precise protection for the negative electrode connecting piece 15, while the second adhesive portion 22 provides auxiliary protection and reinforcement, filling the gaps between the negative electrode connecting piece 15 and the negative electrode tab 14, as well as the gaps between the negative electrode tab 14 and the adjacent core 13, to prevent electrolyte from penetrating onto the negative electrode connecting piece 15.

[0025] See Figure 2As shown, in this embodiment, the negative electrode connecting piece 15 is provided with a negative electrode post 16, and the first adhesive part 20 is provided with a relief groove 21 adapted to the negative electrode post 16. When the first adhesive part 20 is attached to the negative electrode connecting piece 15, the negative electrode post 16 passes through the relief groove 21. The negative electrode post 16 is used to conduct current, and the relief groove 21 is used to prevent the first adhesive part 20 from covering the negative electrode post 16, which would affect the normal operation of the negative electrode post 16. The negative electrode post 16 usually protrudes from the surface of the negative electrode connecting piece 15. If the first adhesive part 20 covers the protruding end of the negative electrode post 16, it will be difficult for the first adhesive part 20 and the negative electrode connecting piece 15 to be flat and tightly attached. The relief groove 21 is adapted to the shape of the negative electrode post 16, reducing the possible uneven bonding area and ensuring that the first adhesive part 20 and the negative electrode connecting piece 15 can be flatly attached.

[0026] See Figure 3 As shown, in this embodiment, a solder mark 17 is formed at the welding joint between the negative electrode connecting piece 15 and the negative electrode tab 14. The second adhesive assembly includes a third adhesive part 40 and a fourth adhesive part 41. The third adhesive part 40 is respectively applied to the connection areas of the negative electrode tab 14 and the core 13 on both sides, and the third adhesive part 40 at least partially covers the solder mark 17 and the surface of the core 13. The fourth adhesive part 41 is applied to the surface of the negative electrode connecting piece 15. The solder mark 17 is prone to problems such as protrusions and uneven edges, and is the position where gaps are most likely to form in traditional adhesive application. The third adhesive part 40 extends from the area of ​​the solder mark 17 to the core 13, filling the gaps at the connection between the negative electrode connecting piece 15 and the negative electrode tab 14, and between the negative electrode tab 14 and the core 13 on the second surface 12. The third adhesive part 40 overlaps with the second adhesive part 22, avoiding the exposed adhesive parts from adhering to other components or welding slag, and further reducing the risk of corrosion. As a preferred approach, the dimensions of the second adhesive portion 22 and the third adhesive portion 40 are both larger than the negative electrode tab 14, thereby expanding the coverage area, reducing blind spots in protection, and preventing the adhesive tape edges from lifting or detaching.

[0027] See Figure 4 As shown, in this embodiment, the fourth adhesive part 41 completely covers the side surface of the negative electrode connecting piece 15 facing away from the first adhesive assembly, and is affixed to the surfaces of the negative electrode connecting piece 15 and part of the cover plate 30. The fourth adhesive part 41 adheres to the second surface 12 of the negative electrode connecting piece 15, preventing the electrolyte from contacting the negative electrode connecting piece 15. The fourth adhesive part 41 adheres to part of the cover plate 30, further fixing the cover plate 30 to the negative electrode connecting piece 15, and simultaneously enhancing the sealing and protection effect in conjunction with the protective range of the third adhesive part 40.

[0028] In one possible implementation, see [link to implementation details]. Figure 4As shown, the size of the fourth adhesive part 41 is larger than the size of the negative electrode connecting piece 15, and the projected area of ​​the fourth adhesive part 41 is within the projected area of ​​the cover plate 30. As the final adhesive application, the fourth adhesive part 41 must completely cover the side of the negative electrode connecting piece 15 facing away from the cover plate 30, and overlap and fix it with the third adhesive tape to avoid gaps between the third adhesive part 40 and the fourth adhesive part 41, preventing electrolyte from seeping through the gaps. It also improves overall protective stability, reduces the risk of the third adhesive part 40 lifting in uneven areas such as the solder mark 17, and provides higher adhesion durability. The adhesive area of ​​the fourth adhesive part 41 does not exceed the two side edges of the cover plate 30 to prevent the fourth adhesive part 41 from curling or lifting. The third adhesive part 40 and the fourth adhesive part 41 can be an integrally molded structure, which is attached to the second surface 12 of the conductive component 10 after the cover plate 30 is welded, or a segmented connection and fixation is adopted. The third adhesive part 40 is attached first, which can fully or at least partially cover the solder mark 17 to prevent the solder slag generated by welding the cover plate 30 from falling onto the junction of the negative electrode connecting piece 15 and the negative electrode tab 14 and the junction of the negative electrode tab 14 and the core 13. After the cover plate 30 is welded, the fourth adhesive part 41 is attached and partially overlaps with the third adhesive part 40 and the cover plate 30 to provide reinforcement and protection, prevent the electrolyte from seeping from the second surface 12 to the negative electrode connecting piece 15 during liquid injection, and prevent the adhesive tape from peeling off.

[0029] In this embodiment, both the first and second adhesive application components are any one of the following: electrolyte-resistant PET adhesive paper, PP adhesive paper, PC adhesive paper, and PVC adhesive paper. These types of adhesive papers possess electrolyte-resistant properties, preventing swelling, cracking, or adhesive failure caused by prolonged immersion in electrolyte. They effectively maintain insulation and fixation, reducing the risk of battery failure.

[0030] Furthermore, both the first and second adhesive application components are made of high-temperature resistant adhesive tape. Under battery charging and discharging, high-temperature storage, or extreme operating conditions, the internal temperature rises, and the high-temperature resistant adhesive tape can prevent the tape from softening, delaminating, decomposing, or losing its adhesiveness, ensuring its good insulation and protective functions.

[0031] The above description, based on the embodiments shown in the drawings, details the structure, features, and effects of this utility model. The above description is only a preferred embodiment of this utility model, but the scope of implementation of this utility model is not limited to what is shown in the drawings. Any changes made in accordance with the concept of this utility model, or modifications to equivalent embodiments, that do not exceed the spirit covered by the specification and drawings, shall be within the protection scope of this utility model.

Claims

1. A battery top cover adhesive structure, characterized in that, include: A conductive component having a first surface and a second surface arranged opposite to each other, the conductive component including a core, a negative electrode tab and a negative electrode connecting piece, the negative electrode tabs being led out from opposite ends of the two cores respectively, and the two ends of the negative electrode connecting piece being welded to the negative electrode tabs on both sides respectively. The first adhesive assembly is applied to the first surface, and the first adhesive assembly covers the negative electrode connecting piece and extends to the core area on both adjacent sides. A cover plate is used to cover the first adhesive assembly and weld it to the negative electrode connecting piece. The second adhesive assembly is applied to the second surface and corresponds to the position of the first adhesive assembly. The second adhesive assembly covers the negative electrode connecting piece and extends to the adjacent core area, and covers at least part of the cover plate.

2. The battery top cover taping structure according to claim 1, wherein, The first adhesive application assembly includes a first adhesive application part and a second adhesive application part. The first adhesive application part covers the surface of the negative electrode connecting piece, and the second adhesive application part is respectively applied to the connection areas of the negative electrode tab and the winding core on both sides.

3. The battery top cover taping structure of claim 2, wherein, The second adhesive portion covers a portion of the first adhesive portion and a portion of the core surface.

4. The battery top cover taping structure of claim 2, wherein, The negative electrode connecting piece is provided with a negative electrode post, and the first adhesive part is provided with a relief groove adapted to the negative electrode post. When the first adhesive part is attached to the negative electrode connecting piece, the negative electrode post passes through the relief groove.

5. The battery top cover taping structure of claim 1, wherein, The negative electrode connecting piece and the negative electrode tab are welded together with a solder mark. The second adhesive part includes a third adhesive part and a fourth adhesive part. The third adhesive part is respectively applied to the connection area between the negative electrode tab and the core on both sides, and the third adhesive part at least partially covers the solder mark and the surface of the core. The fourth adhesive part is applied to the surface of the negative electrode connecting piece.

6. The battery top cover taping structure of claim 5, wherein, The fourth adhesive part completely covers the surface of the negative electrode connecting piece, and at least partially covers the third adhesive part and the cover plate.

7. The battery top cover taping structure according to claim 6, wherein, The size of the fourth adhesive part is larger than the size of the negative electrode connecting piece, and the projected area of ​​the fourth adhesive part is within the projected area of ​​the cover plate.

8. The battery top cover taping structure of claim 1, wherein, The first adhesive application component and the second adhesive application component are any one of the following: electrolyte-resistant PET adhesive paper, PP adhesive paper, PC adhesive paper, and PVC adhesive paper.

9. The battery top cover adhesive structure according to claim 1, characterized in that, Both the first adhesive application component and the second adhesive application component are high-temperature resistant adhesive tapes.

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