Top cover assembly and battery

Abstract

The utility model relates to battery technical field discloses a top cover subassembly and battery. The battery includes casing, top cover subassembly and electric core, and the electric core sets up in the casing, and the top cover subassembly includes top cover sheet, positive pole post and positive pole adapter piece, and the positive pole post installs on the top cover sheet, and the positive pole post includes copper pole post part and aluminium pole post part, and the positive pole adapter piece includes the aluminium connecting layer and copper connecting layer of interconnection, and the aluminium connecting layer is configured as with the positive pole lug welding connection of electric core, and the copper connecting layer and copper pole post part of positive pole post welding connection. The top cover subassembly of the utility model can make the internal resistance of battery positive pole reduce, reduce the heat output of positive pole under the large current working condition, improve battery energy efficiency and cycle life.

Description

Technical Field

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

[0002] Traditional power batteries typically consist of a casing, a top cover assembly, and battery cells. The battery cells are housed inside the casing, and the top cover assembly covers the open end of the casing. The positive and negative tabs of the battery cells are connected to the positive and negative terminals in the top cover assembly via adapter plates.

[0003] Typically, the positive electrode tab is made of aluminum and is connected to the aluminum positive terminal via an aluminum adapter. However, the conductivity of aluminum (approximately 35.5 MS / m) is significantly lower than that of copper (approximately 58.5 MS / m), resulting in higher battery resistance, high internal resistance under high current conditions, severe heat generation, and impact on battery energy efficiency and cycle life.

[0004] Therefore, there is an urgent need for a top cover assembly and battery to solve the above problems. Utility Model Content

[0005] One objective of this invention is to provide a top cover assembly that can reduce the internal resistance of the battery positive electrode, reduce the heat generation of the positive electrode under high current conditions, and improve battery energy efficiency and cycle life.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] Top cover assembly, including:

[0008] Top cover plate;

[0009] A positive electrode post is mounted on the top cover plate, and the positive electrode post includes a copper electrode post portion and an aluminum electrode post portion;

[0010] The positive electrode adapter includes an aluminum connecting layer and a copper connecting layer connected together. The aluminum connecting layer is configured to be welded to the positive electrode tab of the battery cell, and the copper connecting layer is welded to the copper electrode portion of the positive electrode post.

[0011] As an alternative, the aluminum connecting layer is attached to the side of the copper connecting layer opposite to the positive electrode post, and the copper connecting layer is welded to the aluminum connecting layer.

[0012] As an alternative, the outer contour shape of the copper connecting layer is the same as that of the aluminum connecting layer and the same size. The aluminum connecting layer is provided with a clearance hole, which is configured to prevent the copper connecting layer from being welded to the positive electrode post.

[0013] As an alternative, the copper interconnect layer includes a first functional area and a second functional area, wherein the first functional area is used for welding connection with the positive electrode post, and the aluminum interconnect layer is attached to the second functional area.

[0014] As an alternative, a positioning groove is provided on the side of the copper connecting layer away from the positive electrode post, and the aluminum connecting layer is fixed in the positioning groove.

[0015] As an optional embodiment, the copper interconnect layer includes two spaced-apart connecting portions, each of which is attached to an aluminum interconnect layer on the side facing away from the positive terminal post. The aluminum interconnect layers at the two connecting portions are respectively used to connect to the positive terminals of different battery cells, wherein:

[0016] The aluminum connecting layers at the two connecting portions are integrally formed; or

[0017] The aluminum connecting layers at the two connecting portions are spaced apart.

[0018] As an optional solution, the thickness of the aluminum connecting layer is 0.2mm to 0.5mm; and / or the thickness of the copper connecting layer is 0.3mm to 0.8mm.

[0019] As an alternative, the copper electrode portion is at least partially located inside the top cover plate and connected to the copper connecting layer, while the aluminum electrode portion is at least partially located outside the top cover plate.

[0020] As an alternative, along the axial direction of the positive electrode post, the height of the copper electrode portion accounts for 40% to 60% of the total height of the positive electrode post; and / or

[0021] The top cover assembly also includes a negative terminal post and a negative terminal adapter piece. The negative terminal adapter piece connects the negative terminal post and the negative terminal tab of the battery cell. The structure of the negative terminal post is the same as that of the positive terminal post.

[0022] Another objective of this invention is to propose a battery that, by adopting the aforementioned top cover assembly, reduces internal resistance, generates less heat at the positive electrode under high current conditions, and achieves high battery energy efficiency and long cycle life.

[0023] To achieve this objective, the present invention adopts the following technical solution:

[0024] The battery includes a casing, a cell, and the top cover assembly, wherein the positive electrode tab of the cell is connected to the aluminum bonding layer.

[0025] The beneficial effects of this utility model are:

[0026] The top cover assembly of this utility model, by setting the positive electrode adapter piece to include a copper connecting layer and an aluminum connecting layer, and setting the positive electrode post to include a copper electrode post portion and an aluminum electrode post portion, and welding the aluminum connecting layer to the positive electrode tab of the battery, and welding the copper connecting layer to the copper electrode post portion of the positive electrode post, can not only ensure the reliability of the connection between the adapter piece and the positive electrode tab and the positive electrode post respectively, but also increase the overall copper material and reduce the aluminum material of the positive electrode, thereby reducing the internal resistance of the battery, reducing the heat generation of the positive electrode under high current conditions, and thus improving the battery energy efficiency and cycle life.

[0027] The battery of this invention, by adopting the above-mentioned top cover assembly, has reduced internal resistance, less heat generation at the positive electrode under high current conditions, and high energy efficiency and long cycle life. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the battery structure provided in a specific embodiment of the present invention;

[0029] Figure 2 This is an exploded view of the battery provided in a specific embodiment of this utility model;

[0030] Figure 3 This is a cross-sectional view of the top cover assembly provided in a specific embodiment of this utility model;

[0031] Figure 4 yes Figure 3 Enlarged view of point A in the image;

[0032] Figure 5 This is a schematic diagram of the structure of the first positive electrode adapter provided in a specific embodiment of this utility model;

[0033] Figure 6 yes Figure 5 Exploded view of the positive electrode adapter plate in the middle;

[0034] Figure 7 This is a schematic diagram of the structure of the second positive electrode adapter provided in a specific embodiment of this utility model;

[0035] Figure 8 yes Figure 7 Exploded view of the positive electrode adapter plate in the middle;

[0036] Figure 9 This is a schematic diagram of the structure of the third positive electrode adapter provided in a specific embodiment of this utility model;

[0037] Figure 10 yes Figure 9 Exploded view of the positive electrode adapter plate.

[0038] In the picture:

[0039] 10. Top cover assembly; 11. Top cover plate; 12. Positive electrode post; 121. Copper electrode post portion; 122. Aluminum electrode post portion; 13. Positive electrode adapter plate; 131. Copper connecting layer; 1311. Clearance hole; 1312. First functional area; 1313. Second functional area; 1314. Positioning groove; 1315. Connecting part; 132. Aluminum connecting layer; 14. Negative electrode post; 15. Lower plastic; 16. Upper plastic; 17. Negative electrode adapter plate;

[0040] 20. Shell; 21. Opening;

[0041] 30. Battery cell; 31. Positive tab; 32. Negative tab; 33. Battery cell body. Detailed Implementation

[0042] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not the entire structure.

[0043] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0044] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0045] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0046] This embodiment provides a top cover assembly and a battery, such as Figure 1 and Figure 2 As shown, the battery includes a casing 20, a battery cell 30, and a top cover assembly 10. One end of the casing 20 has an opening 21, through which the battery cell 30 can be inserted. The top cover assembly 10 is electrically connected to the battery cell 30 and seals the opening 21 of the casing 20. In this embodiment, the battery is a prismatic battery, and the casing 20 is generally constructed as a cuboid shell, with an opening 21 formed on one side. The battery cell 30 includes a cell body 33, a positive electrode tab 31, and a negative electrode tab 32. The positive electrode tab 31 and the negative electrode tab 32 are located on the same side of the cell body 33. The positive electrode tab 31 is made of aluminum, and the negative electrode tab 32 is made of copper.

[0047] like Figure 3 and Figure 4 As shown, the top cover assembly 10 includes a top cover plate 11, a positive terminal 12, a negative terminal 14, a positive adapter plate 13, and a negative adapter plate 17. Both the positive terminal 12 and the negative terminal 14 are mounted on the top cover plate 11. The positive adapter plate 13 connects the positive terminal 12 to the positive tab 31 of the battery cell 30, and the negative adapter plate 17 connects the negative terminal 14 to the negative tab 32. In this embodiment, the battery includes two battery cells 30, which are connected in parallel. Therefore, the positive tabs 31 of both battery cells 30 are connected to the positive adapter plate 13, and the negative tabs 32 of both battery cells 30 are connected to the negative adapter plate 17. Specifically, the top cover plate 11 has two mounting through holes, and the positive terminal 12 and the negative terminal 14 each pass through one mounting through hole and are fixed within the corresponding mounting through hole. Optionally, the positive terminal 12 and the negative terminal 14 can be mounted on the top cover plate 11 by riveting.

[0048] In this embodiment, as Figure 4 and Figure 5As shown, the top cover assembly 10 also includes components such as an upper plastic 16, a lower plastic 15, and a sealing element. The upper plastic 16 and the lower plastic 15 are used to insulate the positive terminal 12 and the top cover plate 11, and to insulate the negative terminal 14 and the top cover plate 11. The sealing element is used to seal the mounting positions of the positive terminal 12 and the negative terminal 14. It is understood that, without departing from the inventive concept of this application, the specific structure of the upper plastic 16, the lower plastic 15, and the sealing element, and the fixed connection method between the positive terminal 12 and the negative terminal 14 and the top cover plate 11 can be any of the prior art.

[0049] In this embodiment, the negative electrode adapter 17 is connected to the negative electrode tab 32 and the negative electrode post 14 by welding. Since the negative electrode tab 32 is made of copper, the negative electrode adapter 17 is also made of copper. The negative electrode post 14 is at least partially made of copper. The copper-made negative electrode adapter 17 is welded to the copper-made negative electrode tab 32 and the copper-made portion of the negative electrode post 14, respectively. The welding is convenient and the connection is highly reliable.

[0050] In the prior art, the positive electrode adapter 13 is connected to the positive electrode tab 31 and the positive electrode post 12 by welding. Since the positive electrode tab 31 is made of aluminum, both the positive electrode adapter 13 and the positive electrode post 12 are made of aluminum to facilitate reliable welding. However, the conductivity of aluminum (approximately 35.5 MS / m) is significantly lower than that of copper (approximately 58.5 MS / m), resulting in higher battery resistance, high internal resistance under high current conditions, severe heat generation, and impact on battery energy efficiency and cycle life.

[0051] In this regard, such as Figure 4 and Figure 5 As shown, at least a portion of the positive electrode post 12 is made of copper, such that the positive electrode post 12 includes a copper electrode post portion 121 and an aluminum electrode post portion 122. The positive electrode adapter 13 includes an aluminum connecting layer 132 and a copper connecting layer 131 connected together. The aluminum connecting layer 132 is welded to the positive electrode tab 31 (made of aluminum) of the battery cell 30, and the copper connecting layer 131 is welded to the copper electrode post portion 121 of the positive electrode post 12. This arrangement ensures the convenience and reliability of welding the positive electrode adapter 13 to the positive electrode tab 31 and the positive electrode post 12 respectively, and increases the amount of copper material and reduces the amount of aluminum material in the positive electrode of the battery, thereby reducing the internal resistance of the battery and the heat generation of the positive electrode under high current conditions, thus improving the battery energy efficiency and cycle life.

[0052] like Figure 4As shown, the positive electrode post 12 includes a copper electrode post 121 and an aluminum electrode post 122 welded together. The copper electrode post 121 is at least partially located inside the top cover plate 11 (specifically, the side of the top cover plate 11 facing inwards towards the housing 20) and is welded to the copper connecting layer 131. The aluminum electrode post 122 is at least partially located outside the top cover plate 11 (specifically, the side of the top cover plate 11 facing outwards towards the housing 20). By setting the positive electrode post 12 to include the copper electrode post 121, which is at least partially located inside the top cover plate 11, it is possible to reliably weld the positive electrode post 12 to the copper connecting layer 131 of the positive electrode adapter 13 and to minimize the resistance of the battery positive electrode. Since aluminum has good heat dissipation properties, setting the positive electrode post 12 to include the aluminum electrode post 122, which is at least partially located outside the top cover plate 11, helps to dissipate the heat generated after the positive electrode post 12 is energized to the outside of the battery cell 30 more smoothly, thereby reducing the risk of overheating of the battery cell 30 and improving the battery's lifespan. Optionally, in this embodiment, the copper electrode portion 121 and the aluminum electrode portion 122 are joined together by friction welding, resulting in high connection reliability.

[0053] In this embodiment, the copper electrode portion 121 and the aluminum electrode portion 122 are arranged along the axial direction of the positive electrode 12, and the height of the copper electrode portion 121 accounts for 40% to 60% of the total height of the positive electrode 12. By setting the height percentage of the copper electrode portion 121 within the above range, the positive electrode 12 can achieve both good heat dissipation and advantages such as low internal resistance and high conductivity. Optionally, the height percentage of the copper electrode portion 121 to the total height of the positive electrode 12 can be 40%, 45%, 50%, 55%, 60%, etc., and is not specifically limited here. In this embodiment, the cross-section of the portion of the copper electrode portion 121 located inside the top cover plate 11 along the axial direction is larger than the cross-section of the mounting through hole, and the cross-section of the portion of the aluminum electrode portion 122 located outside the top cover plate 11 along the axial direction is larger than the cross-section of the mounting through hole. Thus, the portion of the copper electrode portion 121 with a cross-section larger than the mounting through hole and the portion of the aluminum electrode portion 122 with a cross-section larger than the mounting through hole can achieve axial positioning and fixation of the positive electrode 12.

[0054] In this embodiment, the structure of the negative electrode post 14 is the same as that of the positive electrode post 12. On the one hand, the copper electrode post 121 of the negative electrode post 14 is made of the same material as the negative electrode adapter piece 17 made of copper, which facilitates welding; on the other hand, the aluminum electrode post 122 of the negative electrode post 14 can ensure good heat dissipation of the negative electrode post 14, thereby reducing the risk of overheating of the cell 30 and improving the battery's service life; furthermore, setting the positive electrode post 12 and the negative electrode post 14 to have the same structure can reduce the types of battery components, facilitate mass production, and thus reduce the manufacturing cost of the battery.

[0055] like Figure 4 and Figure 5As shown, the aluminum interconnect layer 132 is bonded to the copper interconnect layer 131 on the side facing the positive electrode post 12, and the copper interconnect layer 131 and the aluminum interconnect layer 132 are welded together. Optionally, the copper interconnect layer 131 and the aluminum interconnect layer 132 can be bonded together by explosive welding. After explosive welding, a copper-aluminum eutectic layer is formed between the copper interconnect layer 131 and the aluminum interconnect layer 132. This copper-aluminum eutectic layer can reduce the interface resistance between the copper interconnect layer 131 and the aluminum interconnect layer 132, thereby improving the battery energy efficiency and cycle life.

[0056] Based on the requirements for overcurrent performance, the thickness of existing aluminum adapter sheets is typically around 1.5 mm, and the thickness of copper adapter sheets is around 0.8 mm. In this embodiment, the thickness of the aluminum connecting layer 132 in the positive electrode adapter sheet 13 is 0.2 mm to 0.5 mm, and the thickness of the copper connecting layer 131 is 0.3 mm to 0.8 mm. This configuration allows the positive electrode adapter sheet 13 to meet the overcurrent performance requirements while significantly reducing its thickness compared to existing aluminum adapter sheets. This reduces the space occupied by the positive electrode adapter sheet 13 within the battery, thereby facilitating a more compact battery design and improving the battery's energy density. Optionally, in this embodiment, the specific thickness of the aluminum connecting layer 132 can be 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, etc., and is not limited here. The thickness of the copper connecting layer 131 can be 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, etc., and is not specifically limited here.

[0057] In some embodiments, such as Figure 5 and Figure 6 As shown, the outer contour shape of the copper connecting layer 131 is the same as that of the aluminum connecting layer 132 and the same size. The aluminum connecting layer 132 has a clearance hole 1311, configured to prevent the copper connecting layer 131 from being welded to the positive electrode post 12. By setting the outlines of the copper connecting layer 131 and the aluminum connecting layer 132 to be the same in shape and size, the copper connecting layer 131 and the aluminum connecting layer 132 can be manufactured using the same mold, thereby reducing the manufacturing cost of the positive electrode adapter 13 and consequently reducing the battery manufacturing cost. By providing the clearance hole 1311 on the aluminum connecting layer 132, when welding the positive electrode adapter 13 to the positive electrode post 12, the side of the copper connecting layer 131 facing away from the clearance hole 1311 abuts against the positive electrode post 12, and the copper electrode post portion 121 of the positive electrode post 12 is welded from the clearance hole 1311, making the operation more convenient.

[0058] In some embodiments, such as Figure 7 and Figure 8As shown, the copper interconnect layer 131 includes a first functional region 1312 and a second functional region 1313. The first functional region 1312 is used for welding to the positive electrode post 12, and the aluminum interconnect layer 132 is attached to the second functional region 1313. That is, the aluminum interconnect layer 132 only adheres to and covers the second functional region 1313 of the copper interconnect layer 131. On the one hand, when the positive electrode adapter 13 is connected to the positive electrode post 12, welding can be performed directly in the first functional region 1312 without the need for additional processing of the clearance hole 1311. On the other hand, it can further reduce the volume ratio of aluminum material in the positive electrode adapter 13, thereby reducing the resistance of the battery positive electrode and reducing the heat generated by the battery positive electrode under high current conditions, thus improving the battery energy efficiency and cycle life.

[0059] like Figures 7-10 As shown, a positioning groove 1314 is provided on the side of the copper connector layer 131 facing away from the positive electrode post 12, and the aluminum connector layer 132 is fixed in the positioning groove 1314. By providing the positioning groove 1314, the installation of the aluminum connector layer 132 can be positioned, ensuring the positional accuracy of the copper connector layer 131 and the aluminum connector layer 132, and thus accurately welding to the positive electrode post 12 and the positive electrode tab 31 respectively. In addition, the aluminum connector layer 132 being housed in the positioning groove 1314 also helps to further reduce the total thickness of the positive electrode adapter piece 13. In this embodiment, the depth of the positioning groove 1314 is the same as the thickness of the aluminum connector layer 132.

[0060] In this embodiment, the copper connection layer 131 includes two spaced connection portions 1315. Each connection portion 1315 is attached to an aluminum connection layer 132 on the side away from the positive electrode post 12. The positive electrode tabs 31 of the two cells 30 are respectively connected to the aluminum connection layers 132 at different connection portions 1315.

[0061] In some embodiments, such as Figure 7 and Figure 8 As shown, the aluminum connecting layers 132 at the two connecting portions 1315 are integrally formed, meaning that the positive electrode adapter 13 includes only one independent aluminum connecting layer 132, which makes it easier to process. In this embodiment, a positioning groove 1314 is provided on the copper connecting layer 131 to install the aluminum connecting layer 132.

[0062] In some embodiments, such as Figure 9 and Figure 10As shown, the aluminum connecting layers 132 at the two connecting portions 1315 are spaced apart. That is, one positive electrode adapter 13 includes two independent aluminum connecting layers 132. This arrangement minimizes the volume ratio of aluminum material in the positive electrode adapter 13, thereby further reducing the resistance of the battery positive electrode and the heat generated by the battery positive electrode under high current conditions, improving battery energy efficiency and cycle life. In this embodiment, a positioning groove 1314 is correspondingly provided at each connecting portion 1315 of the copper connecting layer 131, and two positioning grooves 1314 respectively position and install one aluminum connecting layer 132.

[0063] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. For those skilled in the art, based on the concept of this utility model, there will be changes in the specific implementation methods and application scope. The content of this specification should not be construed as a limitation of this utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A top cover assembly, characterized in that, include: Top cover plate (11); A positive electrode post (12) is mounted on the top cover plate (11), and the positive electrode post (12) includes a copper electrode post portion (121) and an aluminum electrode post portion (122); The positive electrode adapter (13) includes an aluminum connecting layer (132) and a copper connecting layer (131) connected together. The aluminum connecting layer (132) is configured to be welded to the positive electrode tab (31) of the battery cell (30), and the copper connecting layer (131) is welded to the copper electrode post (121) of the positive electrode post (12).

2. The top cover assembly as claimed in claim 1, characterized in that, The aluminum connecting layer (132) is attached to the side of the copper connecting layer (131) away from the positive electrode post (12), and the copper connecting layer (131) is welded to the aluminum connecting layer (132).

3. The top cover assembly as described in claim 2, characterized in that, The outer contour shape of the copper connecting layer (131) is the same as that of the aluminum connecting layer (132) and the same size. The aluminum connecting layer (132) is provided with a clearance hole (1311), which is configured to avoid the copper connecting layer (131) from being welded to the positive electrode post (12).

4. The top cover assembly as claimed in claim 2, characterized in that, The copper connection layer (131) includes a first functional area (1312) and a second functional area (1313). The first functional area (1312) is used for welding connection with the positive electrode post (12), and the aluminum connection layer (132) is attached to the second functional area (1313).

5. The top cover assembly as claimed in claim 4, characterized in that, The copper connecting layer (131) is provided with a positioning groove (1314) on the side opposite to the positive electrode post (12), and the aluminum connecting layer (132) is fixed in the positioning groove (1314).

6. The top cover assembly as claimed in claim 2, characterized in that, The copper interconnect layer (131) includes two spaced-apart interconnects (1315), and the aluminum interconnect layer (132) is attached to the side of each interconnect (1315) facing away from the positive electrode post (12). The aluminum interconnect layer (132) at the two interconnects (1315) is used to connect to the positive electrode tab (31) of different cells (30), wherein: The aluminum connecting layer (132) at the two connecting portions (1315) is integrally formed; or The aluminum connecting layers (132) at the two connecting portions (1315) are spaced apart.

7. The top cover assembly as claimed in claim 1, characterized in that, The thickness of the aluminum connecting layer (132) is 0.2 mm to 0.5 mm; and / or the thickness of the copper connecting layer (131) is 0.3 mm to 0.8 mm.

8. The top cover assembly as claimed in any one of claims 1-7, characterized in that, The copper electrode portion (121) is at least partially located inside the top cover plate (11) and connected to the copper connecting layer (131), while the aluminum electrode portion (122) is at least partially located outside the top cover plate (11).

9. The top cover assembly as claimed in claim 8, characterized in that, Along the axial direction of the positive electrode post (12), the height of the copper electrode post portion (121) accounts for 40% to 60% of the total height of the positive electrode post (12); and / or The top cover assembly also includes a negative terminal post (14) and a negative terminal adapter (17). The negative terminal adapter (17) connects the negative terminal post (14) and the negative terminal tab (32) of the battery cell (30). The structure of the negative terminal post (14) is the same as that of the positive terminal post (12).

10. A battery, characterized in that, The device includes a housing (20), a battery cell (30), and a top cover assembly as described in any one of claims 1-9, wherein the positive tab (31) of the battery cell (30) is connected to the aluminum connecting layer (132).

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