Pole, top cover assembly and battery cell

Abstract

The utility model provides a pole column, a top cover assembly and a battery cell, and belongs to the technical field of batteries, the pole column comprises a first metal piece and a second metal piece which are stacked along a first direction; the first metal piece is provided with a first protruding part protruding in the first direction, the second metal piece is provided with a first concave part, and the first protruding part is embedded in the first concave part. The maximum thickness of the first metal piece at the first convex part in the first direction is H1, the corresponding thickness of the second metal piece at the maximum thickness of the first metal piece in the first direction is H2, and H1 / H2 is larger than or equal to 0.25 and smaller than or equal to 1.55; wherein the first metal piece and the second metal piece are made of different materials. According to the pole provided by the embodiment of the invention, the structural stability of the pole is ensured and the resistance value is reduced while the cost of the pole is reduced.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to an electrode post, a top cover assembly, and a battery cell. Background Technology

[0002] In the field of new energy vehicles, batteries typically use aluminum and copper as the positive and negative electrode materials, respectively. If the negative electrode post is made of pure copper, it will result in higher costs. Furthermore, when a pure copper negative electrode post is welded to an aluminum terminal, the difference in melting points between the two materials can easily lead to welding failure and subsequent cracking of the weld structure.

[0003] In related technologies, to reduce the cost of the negative electrode post and improve the welding stability between the negative electrode post and the terminal, a layered electrode post with an upper part of aluminum and a lower part of copper is usually used. However, welding between the aluminum layer and the copper layer is difficult, and intermediate compounds are easily formed between copper and aluminum, leading to an increase in resistance and thus affecting the electrical performance of the battery cell. Utility Model Content

[0004] The embodiments of this application provide a terminal post, a battery cell, and a battery pack, which can reduce the cost of the terminal post while ensuring its structural stability and reducing its resistance.

[0005] In a first aspect, embodiments of this application provide a pole post, including a first metal member and a second metal member stacked along a first direction;

[0006] The first metal part is provided with a first protrusion that protrudes along a first direction, and the second metal part is provided with a first recess, wherein the first protrusion is fitted into the first recess.

[0007] The first metal part has a maximum thickness of H1 at the first protrusion in the first direction, and the second metal part has a corresponding thickness of H2 at the maximum thickness of the first metal part in the first direction, satisfying: 0.4≤H1 / H2≤1.55;

[0008] The first metal part and the second metal part are made of different materials.

[0009] In some embodiments, 0.4 ≤ H1 / H2 ≤ 1.55.

[0010] In some embodiments, 0.5 ≤ H1 / H2 ≤ 1.0.

[0011] In some embodiments, a reverse wrapping structure is provided on the periphery of the first metal part, and a second recess is formed between the reverse wrapping structure and the first protrusion.

[0012] The second metal part has a second protrusion on its periphery;

[0013] The second protrusion is fitted into the second recess and is engaged with the first metal part by means of a reverse wrapping structure and the first protrusion.

[0014] In some embodiments, the maximum width of the second metal member in the second direction is W1, the thickness of the first protrusion in the first direction is H3, the region in the first protrusion where H3 / H1≥0.6 forms the first protrusion interval, and the maximum width of the first protrusion interval in the second direction is W2, satisfying: 0<W2 / W1≤0.7.

[0015] The second direction is perpendicular to the first direction.

[0016] In some embodiments, a reverse wrapping structure is provided on the periphery of the first metal part, and a second recess is formed between the reverse wrapping structure and the first protrusion.

[0017] The second metal part has a second protrusion on its periphery;

[0018] The second protrusion is fitted into the second recess and is engaged with the first metal part by means of a reverse wrapping structure and the first protrusion.

[0019] In some embodiments, the reverse-wrapping structure has an arcuate protrusion that bulges along a second direction, and the second metal member forms an arcuate recess corresponding to the arcuate protrusion.

[0020] In some embodiments, the maximum protrusion width of the arcuate protrusion in the second direction is W3, satisfying 0 < W3 / W1 ≤ 0.3.

[0021] In some embodiments, a protrusion protruding from the outer periphery of the first metal member is provided on the periphery of the first metal member.

[0022] In some embodiments, the maximum thickness of the first metal member at the inverted structure along the first direction is greater than the thickness of the protrusion along the first direction.

[0023] In some embodiments, the thickness of the protrusion along the first direction is H4, and the maximum thickness of the first metal part at the reverse-wrapping structure along the first direction is H5, satisfying that 0 < H5 - H4 ≤ 0.1 mm.

[0024] In some embodiments, the second metal part is provided with a first step structure and a second step structure;

[0025] The second step structure is located at the end of the second metal part away from the first metal part, and the first step structure is located between the protrusion and the second step structure.

[0026] In some embodiments, the first metal part is made of copper and the second metal part is made of aluminum.

[0027] Secondly, embodiments of this application also provide a top cover assembly, including the pole as described above.

[0028] In some embodiments, a cover plate is also included;

[0029] The cover plate has through holes, through which the pole is inserted into the cover plate.

[0030] In some embodiments, an insulating element and a sealing ring are also included;

[0031] The sealing ring is fitted onto the pole post, and the pole post is in sealed contact with the cover plate through the sealing ring. The pole post is also kept insulated from the cover plate through an insulating component.

[0032] In some embodiments, a terminal clamping block is also included, through which the pole is pressed onto the cover plate.

[0033] Fourthly, embodiments of this application also provide a battery cell, including a housing, a core package, and a top cover assembly as described above, wherein the core package is disposed within the housing, and the top cover assembly is fastened to the opening end of the housing.

[0034] The beneficial effects of the embodiments of this application are as follows:

[0035] In embodiments of this application, the electrode post includes a first metal member and a second metal member stacked along a first direction. The first metal member has a first protrusion protruding along the first direction, and the second metal member has a first recess, with the first protrusion fitting into the first recess. The first metal member has a maximum thickness H1 at the first protrusion in the first direction, and the second metal member has a corresponding thickness H2 at the maximum thickness of the first metal member in the first direction, satisfying: 0.25 ≤ H1 / H2 ≤ 1.55. The first and second metal members are made of different materials. By stacking first and second metal members of different materials, the connection stability between the electrode post and the inside and outside of the battery cell can be ensured, while the cost of the electrode post can be reduced through material selection. The fitting of the first protrusion on the first metal member and the first recess on the second metal member increases the bonding area between the first and second metal members, ensuring the structural stability of the electrode post. Furthermore, by making the maximum thickness of the first metal part at the first protrusion H1 and the thickness of the second metal part at the corresponding maximum thickness of the first metal part H2, satisfying the relationship 0.25≤H1 / H2≤1.55, the resistance of the electrode post can be reduced, and the first metal layer and the second metal layer can produce a good mutual penetration effect at the bonding interface, thus ensuring the structural stability of the electrode post. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the cross-sectional structure of a pole provided in an embodiment of this application. Figure 1 ;

[0038] Figure 2 This is a schematic diagram of the cross-sectional structure of a pole provided in an embodiment of this application. Figure 2 ;

[0039] Figure 3 This is a schematic diagram of the cross-sectional structure of a pole provided in an embodiment of this application. Figure 3 ;

[0040] Figure 4 This is a schematic diagram of another cross-sectional structure of a pole provided in an embodiment of this application;

[0041] Figure 5 This is a schematic diagram of the structure of the first metal layer and the second metal layer provided in the embodiments of this application;

[0042] Figure 6 This is a schematic diagram of the flow region in the pole provided in an embodiment of this application;

[0043] Figure 7 This is a schematic diagram of the top cover assembly provided in an embodiment of this application.

[0044] Explanation of reference numerals in the attached figures:

[0045] 100. Pole post; 1. First metal component; 11. First protrusion; 111. First protrusion section; 12. Reverse wrapping structure; 13. Second recess; 14. Protrusion; 15. First flow region; 16. Second flow region; 17. Third flow region; 2. Second metal component; 21. First recess; 22. Second protrusion; 23. First step structure; 24. Second step structure; 3. First metal layer; 4. Second metal layer;

[0046] 200. Cover plate; 210. Insulating component; 211. First insulating component; 212. Second insulating component; 220. Sealing ring; 230. Terminal clamping block. Detailed Implementation

[0047] The technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Furthermore, it should be understood that the specific implementation methods described herein are only for illustration and explanation of this application and are not intended to limit this application.

[0048] Firstly, such as Figure 1 As shown, an embodiment of this application provides an electrode post 100, which includes a first metal member 1 and a second metal member 2 stacked along a first direction Y. The first metal member 1 has a first protrusion 11 protruding along the first direction Y, and the second metal member 2 has a first recess 21, with the first protrusion 11 fitting into the first recess 21. The maximum thickness of the first metal member 1 at the first protrusion 11 along the first direction Y is H1, and the corresponding thickness of the second metal member 2 at the maximum thickness of the first metal member 1 along the first direction Y is H2, satisfying: 0.4 ≤ H1 / H2 ≤ 1.55. The first metal member 1 and the second metal member 2 are made of different materials. By stacking the first metal member 1 and the second metal member 2 with different materials, the connection stability between the electrode post 100 and the inside and outside of the battery cell can be ensured, and the cost of the electrode post 100 can be reduced by selecting the appropriate materials. The first protrusion 11 on the first metal part 1 and the first recess 21 on the second metal part 2 fit together, which can increase the bonding area between the first metal part 1 and the second metal part 2 and ensure the structural stability of the pole post 100. In addition, by satisfying the relationship 0.25≤H1 / H2≤1.55, the resistance of the pole post 100 can be reduced, and the first metal layer 3 and the second metal layer 4 can produce a good mutual penetration effect at the bonding interface, thus ensuring the structural stability of the pole post 100.

[0049] When the maximum thickness of the first metal part 1 at the first protrusion 11 is H1 and the thickness of the second metal part 2 at the corresponding maximum thickness of the first metal part 1 is H2, and the condition 0.25 ≤ H1 / H2 ≤ 1.55 is met, mutual penetration will occur at the interface between the first metal layer 3 and the second metal layer 4, and the penetration effect is good, making the bond between the first metal layer 3 and the second metal layer 4 tighter and improving structural stability. Furthermore, within the above range, the first metal part 1 has good pressure-bearing capacity, and the thickness of the second metal part 2 ensures that it has a large penetration depth and that its internal structure is not damaged when welded to other components, thereby ensuring good welding strength.

[0050] It is understandable that the first protrusion 11 forms a raised surface on the side near the second metal part 2, and the distance between the highest point of the raised surface and the bottom of the first metal part 1 is H1. The distance from the top surface of the second metal part 2 to the highest point of the raised surface is H2.

[0051] In some embodiments, 0.4 ≤ H1 / H2 ≤ 1.55. By satisfying 0.4 ≤ H1 / H2 ≤ 1.55, the interpenetration effect between the first metal part 1 and the second metal part 2 can be improved, thereby enhancing the bonding force between the first metal part 1 and the second metal part 2. Simultaneously, increasing the thickness ratio of the second metal part 2 improves the stability when the second metal part 2 is welded to external components.

[0052] In some embodiments, 0.5 ≤ H1 / H2 ≤ 1.0. By satisfying 0.5 ≤ H1 / H2 ≤ 1.0, the interpenetration effect between the first metal part 1 and the second metal part 2 can be improved, thereby enhancing the bonding force between the first metal part 1 and the second metal part 2. Simultaneously, increasing the thickness ratio of the second metal part 2 improves the stability when the second metal part 2 is welded to external components.

[0053] In some embodiments, such as Figures 2-4 As shown, a reverse-wrapping structure 12 is provided on the periphery of the first metal part 1, and a second recess 13 is formed between the reverse-wrapping structure 12 and the first protrusion 11. A second protrusion 22 is provided on the periphery of the second metal part 2, and the second protrusion 22 is fitted into the second recess 13 and is engaged with the first metal part 1 by the reverse-wrapping structure 12 and the first protrusion 11.

[0054] By cooperating with the anti-wrapping structure 12 and the first protrusion 11 in the first metal part 1, a second protrusion 22 can be formed to wrap around the second metal part 2, thereby improving the connection stability of the first metal part 1 and the second metal part 2. That is, the first metal part 1 and the second metal part 2 are connected by mutual interlocking to form an interlocking structure. At the same time, the first metal part 1 and the second metal part 2 are mutually permeable to improve the connection stability.

[0055] In some embodiments, such as Figure 2 and Figure 4 As shown, the second metal part 2 has a maximum width of W1 in the second direction X, and the first protrusion 11 has a thickness of H3 in the first direction Y. The area in the first protrusion 11 where H3 / H1≥0.6 forms a first protrusion interval 111, and the first protrusion interval 111 has a maximum width of W2 in the second direction X, satisfying: 0<W2 / W1≤0.7. The second direction X and the first direction Y are perpendicular to each other.

[0056] In the application of the pole post 100, it is usually necessary to weld the pole post 100 to other components. During the welding process, a molten pool is formed on the first metal part 1 and the second metal part 2 of the pole post 100. To ensure the welding effect, the first metal part 1 and the second metal part 2 at the welding point need to have a certain thickness. After research, the area in the first protrusion 11 where H3 / H1≥0.6 forms the first protrusion interval 111, which can better ensure the welding quality when welding in the first protrusion interval 111. By making the maximum width W1 of the second metal part 2 in the first direction Y and the maximum width W2 of the first protrusion interval 111 in the second direction X satisfy 0<W2 / W1≤0.7, sufficient space can be reserved for the inverted structure 12, ensuring the size of the inverted structure 12, improving the stability of the interlocking structure between the first metal part 1 and the second metal part 2, and providing sufficient weldable area for the first metal part 1 and the second metal part 2.

[0057] In one embodiment, such as Figure 2 As shown, the pole post 100 is a cylindrical structure, and both the first metal part 1 and the second metal part 2 are cylindrical. The maximum width W1 of the second metal part 2 in the second direction X is the diameter of the second metal part 2. The first protrusion 11 is a cylindrical boss. The thickness H3 of a portion of the first protrusion 11 along the first direction Y satisfies H3 / H1≥0.6, forming the first protrusion interval 111. The thickness of the first metal part 1 within the first protrusion interval 111 is relatively large, which can meet the welding requirements. The maximum width of the first protrusion interval 111 along the second direction X is W2. By making 0<W2 / W1≤0.7, on the one hand, the contact area of ​​the first metal part 1 and the second metal part 2 can be increased, providing sufficient weldable area for the first metal part 1. On the other hand, sufficient space is reserved for the anti-wrapping structure 12 set on the periphery of the first metal part 1, ensuring the size of the anti-wrapping structure 12, so that when the first metal part 1 and the second metal part 2 form an interlocking structure, they can have good structural stability.

[0058] In another embodiment, such as Figure 4As shown, the pole post 100 is also a cylindrical structure, and both the first metal part 1 and the second metal part 2 are cylindrical. The maximum width W1 of the second metal part 2 in the second direction X is the diameter of the second metal part 2. The first protrusion 11 is an arc-shaped protrusion structure and does not form a boss structure. The thickness H3 and H1 of a part of the first protrusion 11 along the first direction Y satisfy H3 / H1≥0.6, forming the first protrusion interval 111. The thickness of the first metal part 1 in the first protrusion interval 111 is relatively large, which can meet the welding requirements. The maximum width of the first protrusion interval 111 along the second direction X is W2. By making 0<W2 / W1≤0.7, on the one hand, the contact area of ​​the first metal part 1 and the second metal part 2 can be increased, providing sufficient weldable area for the first metal part 1. On the other hand, sufficient space is reserved for the anti-wrapping structure 12 set on the periphery of the first metal part 1, ensuring the size of the anti-wrapping structure 12, so that when the first metal part 1 and the second metal part 2 form an interlocking structure, they can have good structural stability.

[0059] In some embodiments, such as Figures 2-4 As shown, the reverse-encasing structure 12 has an arc-shaped protrusion that protrudes along the second direction X, and the second metal part 2 forms an arc-shaped recess at the arc-shaped protrusion.

[0060] By making the reverse-encasing structure 12 have an arc-shaped protrusion that protrudes along the second direction X, and the second metal part 2 forms an arc-shaped depression at the arc-shaped protrusion, the reverse-encasing structure 12 can compress the second metal part 2 at the arc-shaped depression, so that the arc-shaped protrusion and the arc-shaped depression form a barb structure, forming a stable interlocking relationship. Furthermore, the first metal part 1 and the second metal part 2 are mutually squeezed and penetrated at the arc-shaped protrusion and the arc-shaped depression, reducing the risk of interface detachment and improving the axial tensile resistance of the pole post 100.

[0061] In some embodiments, such as Figure 3 and Figure 4 As shown, the maximum protrusion width of the arc-shaped protrusion in the second direction X is W3, which satisfies 0 < W3 / W1 ≤ 0.3.

[0062] By satisfying 0 < W3 / W1 ≤ 0.3, the reverse wrapping structure 12 can cooperate with the first protrusion 11 and the second metal part 2 to form a stable locking structure, ensuring the bonding stability of the first metal part 1 and the second metal part 2, while reducing the manufacturing difficulty of the reverse wrapping structure 12 and ensuring the strength of the reverse wrapping structure 12.

[0063] In some embodiments, such as Figure 1 and Figure 4 As shown, a protrusion 14 protruding from the outer periphery of the first metal part 1 is provided on the periphery of the first metal part 1. The protrusion 14 is adapted to connect with the connecting piece inside the battery cell and helps to snap the terminal 100 onto the cover plate 200.

[0064] The protrusion 14 protrudes from the outer periphery of the first metal part 1 to form a flange boss. On the one hand, it can increase the contact area between the first metal part 1 and the internal connecting piece in the battery cell. On the other hand, the flange boss can fix the first metal part 1 to the cover plate 200 of the battery cell.

[0065] In some embodiments, such as Figure 3 As shown, the maximum thickness of the first metal part 1 along the first direction Y at the inverted structure 12 is greater than the thickness of the protrusion along the first direction Y. By ensuring that the maximum thickness of the first metal part 1 along the first direction Y at the inverted structure 12 is greater than the thickness of the protrusion along the first direction Y, the volume of the inverted structure 12 can be guaranteed, giving the inverted structure 12 good structural strength, ensuring the connection stability of the first metal part 1 and the second metal part 2, and improving the tensile strength of the pole post 100.

[0066] In some embodiments, such as Figure 3 As shown, the thickness of the protrusion 14 along the first direction Y is H4, and the maximum thickness of the first metal part 1 at the reverse wrapping structure 12 along the first direction Y is H5, satisfying that 0 < H5 - H4 ≤ 0.1 mm.

[0067] That is, the first metal part 1 at the reverse wrapping structure 12 protrudes less than 0.1mm relative to the first metal part 1 at the first step structure 23. On the one hand, this ensures the structural strength of the reverse wrapping structure 12 and the connection stability of the first metal part 1 and the second metal part 2. On the other hand, it reduces the phenomenon that the reverse wrapping structure 12 is easily damaged due to excessive protrusion distance.

[0068] In some embodiments, such as Figure 3 As shown, the second metal part 2 is provided with a first step structure 23 and a second step structure 24. The second step structure 24 is located at the end of the second metal part 2 away from the first metal part 1, and the first step structure 23 is located between the protrusion 14 and the second step structure 24.

[0069] The second step structure 24 is located at the end of the second metal part 2 and can be used to cooperate with the external connecting piece to form a battery module. The first step structure 23 is disposed between the protrusion 14 and the second step structure 24 and can be used to cooperate with the terminal clamping block 230 to fix the terminal post 100.

[0070] In some embodiments, the first metal part 1 is made of copper, and the second metal part 2 is made of aluminum. Copper has better conductivity but is more expensive, while aluminum has poorer conductivity but is less expensive. When the electrode post 100 is a negative electrode post 100, the negative electrode connecting piece inside the cell is usually made of copper. By making the first metal part 1 of copper, the first metal part 1 and the negative electrode connecting piece inside the cell are made of the same material, improving welding stability and ensuring good conductivity. The external connecting piece used to connect adjacent cells is usually made of aluminum. By making the second metal part 2 of aluminum, the welding stability between the electrode post 100 and the external connecting piece is ensured, and the overall cost of the electrode post 100 can be reduced by making part of the electrode post 100 of aluminum. In addition, through the structure of the electrode post 100 provided in this application embodiment, the first metal part 1 of copper and the second metal part 2 of aluminum can form a good bond, ensuring connection stability while allowing them to permeate each other, reducing the resistance of the electrode post 100.

[0071] Secondly, embodiments of this application provide a method for preparing an electrode post 100, which is used to prepare the electrode post 100 as described above, comprising:

[0072] A first metal layer 3 and a second metal layer 4 are provided;

[0073] The first metal layer 3 and the second metal layer 4 are stacked along the first direction Y, such as... Figure 5 As shown, a composite structure is formed;

[0074] The composite structure is cold-forged to form a pole post 100 including a first metal part 1 and a second metal part 2; wherein, a first protrusion 11 is formed in the first metal part 1, a first recess 21 is formed in the second metal part 2, and the first protrusion 11 is fitted into the first recess 21.

[0075] The first metal part 1 has a maximum thickness of H1 at the first protrusion 11 in the first direction Y, and the second metal part 2 has a corresponding thickness of H2 at the maximum thickness of the first metal part 1 in the first direction Y, satisfying: 0.4≤H1 / H2≤1.55. The first metal part 1 and the second metal part 2 are made of different materials.

[0076] That is, the pole post 100 provided in this application embodiment is obtained by cold forging the first metal layer 3 and the second metal layer 4 that are stacked together, so that the first metal part 1 and the second metal part 2 are combined into a whole and meet the relevant requirements.

[0077] In some embodiments, such as Figure 5 As shown, the thickness of the first metal layer 3 in the first direction Y is H6, 0mm < H6 ≤ 5mm, and the maximum width of the first metal layer 3 in the second direction X is W4, 3mm < W4 ≤ 50mm.

[0078] The first metal layer 3 is the raw material of the first metal part 1 and is formed by cold heading. By ensuring that the initial thickness of the first metal layer 3 in the first direction Y satisfies 0mm < H6 ≤ 5mm and the maximum width of the first metal layer 3 in the second direction X satisfies 3mm < W4 ≤ 50mm, the parameters of the first metal part 1 after cold heading can be guaranteed.

[0079] In some embodiments, such as Figure 5 As shown, the thickness of the second metal layer 4 in the first direction Y is H7, 0mm < H7 ≤ 10mm, and the maximum width of the second metal layer 4 in the second direction X is W5, 3mm < W5 ≤ 50mm.

[0080] Similar to the first metal layer 3, by ensuring that the initial thickness of the second metal layer 4 in the first direction Y satisfies 0mm < H7 ≤ 10mm, and the maximum width of the second metal layer 4 in the second direction X satisfies 3mm < W4 ≤ 50mm, the parameters of the second metal part 2 after cold heading can be guaranteed, and the proportional requirements between the first metal part 1 and the second metal part 2 can be guaranteed.

[0081] like Figure 6 As shown, by cold forging the first metal layer 3 and the second metal layer 4, a structure as shown in 1- is formed. Figure 3 The pole post 100 shown enables the formation of multiple flow regions on the second metal part 2. The first flow region 15 is formed by extrusion through the reverse-wrapping structure 12, which improves the connection strength between the first metal part 1 and the second metal part 2 and enhances its resistance to axial tension. The second flow region 16 is formed by extrusion through the first protrusion 11. Compared to the traditional planar joint, this allows for a greater thickness of the first metal part 1, enabling good interpenetration between the first metal part 1 and the second metal part 2, improving stability, and ensuring sufficient welding space between the first metal part 1 and the internal connecting piece.

[0082] Furthermore, through the interaction of the first flow region 15 and the second flow region 16, a third flow region 17 can be formed in the second metal part, thereby improving the structural strength of the pole post 100.

[0083] Thirdly, embodiments of this application also provide a top cover assembly, such as... Figure 7 As shown, it includes the pole post 100 as described above.

[0084] The top cover assembly provided in this application embodiment has all the beneficial effects of the pole post 100 as described above, which will not be repeated here.

[0085] In some embodiments, the top cover assembly further includes a cover plate 200. The cover plate 200 is provided with a through hole, through which the electrode post 100 passes. By passing the electrode post 100 through the cover plate 200, one end of the electrode post 100 can be connected to the interior and the other end can be connected to the exterior, thereby supplying power to the outside.

[0086] In some embodiments, the top cover assembly further includes an insulating element 210 and a sealing ring 220. The sealing ring 220 is sleeved on the pole post 100, and the pole post 100 is in sealed contact with the cover plate 200 through the sealing ring 220, while the pole post 100 is kept insulated from the cover plate 200 through the insulating element 210. The insulating element 210 and the sealing ring 220 enable a sealed connection between the pole post 100 and the cover plate 200 and maintain an insulating effect.

[0087] In some embodiments, the top cover assembly further includes a terminal clamping block 230, through which the pole post 100 is pressed onto the cover plate 200. By pressing the pole post 100 onto the cover plate 200 with the terminal clamping block 230, the pole post 100 is fixed, thereby improving the connection stability between the pole post 100 and the cover plate 200.

[0088] Fourthly, embodiments of this application also provide a battery cell, including a housing, a core package, and a top cover assembly as described above, wherein the core package is disposed within the housing, and the top cover assembly is fastened to the opening end of the housing.

[0089] The battery cell provided in this application embodiment has all the beneficial effects of the terminal 100 as described above, which will not be repeated here.

[0090] The embodiments of this application are further illustrated below with reference to specific examples. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of this application. Experimental methods in the following embodiments that do not specify specific conditions are generally performed according to the conditions recommended by the manufacturer.

[0091] Example 1

[0092] In this embodiment, the structure of the pole post 100 is shown in the figure. The first metal part 1 is made of copper, and the second metal part 2 is made of aluminum. The first metal part 1 has a first protrusion 11 and a reverse-wrapping structure 12, and a second recess 13 is formed between the reverse-wrapping structure 12 and the first protrusion 11. The second metal part 2 has a first recess 21 that fits into and connects with the first protrusion 11, and a second protrusion 22 that is engaged between the reverse-wrapping structure and the first protrusion 11. The pole post 100 is obtained by cold forging the first metal layer 3 and the second metal layer 4.

[0093] Wherein, the first metal part 1 has a maximum thickness of H1 at the first protrusion 11 in the first direction Y, and the second metal part 2 has a corresponding thickness of H2 at the maximum thickness of the first metal part 1 in the first direction Y. H1 = 2.1 mm, H2 = 4.2 mm.

[0094] The above-mentioned pole post 100 is assembled into a top cover assembly according to the structure shown in the figure.

[0095] Example 2

[0096] The difference between this embodiment and Embodiment 1 is that H1 = 2.3 mm and H2 = 4.0 mm.

[0097] Example 3

[0098] The difference between this embodiment and Embodiment 1 is that H1 = 2.8 mm and H2 = 3.5 mm.

[0099] Example 4

[0100] The difference between this embodiment and Embodiment 1 is that H1 = 3.1 mm and H2 = 3.2 mm.

[0101] Example 5

[0102] The difference between this embodiment and Embodiment 1 is that H1 = 3.5 mm and H2 = 2.8 mm.

[0103] Example 6

[0104] The difference between this embodiment and Embodiment 1 is that H1 = 3.8 mm and H2 = 2.5 mm.

[0105] Example 7

[0106] The difference between this embodiment and Embodiment 1 is that H1 = 1.8 mm and H2 = 4.5 mm.

[0107] Comparative Example 1

[0108] The difference between this comparative example and Example 1 is that H1 = 4.0 mm and H2 = 2.3 mm.

[0109] The resistance of the pole, the pull-out force of the joint layer of the first metal part and the second metal part, and the bearing pressure of the flange surface were tested in Examples 1-6 and Comparative Examples 1-2. The Z-axis thrust of the top cover assembly in Examples 1-6 and Comparative Examples 1-2 was also tested. The resistance testing method was as follows: The internal resistance between the exposed end of the electrode and the plate in Examples 1-6 and Comparative Examples 1-2 was measured using an internal resistance meter (decibels), and the data was recorded. The pull-out force testing method for the bonding layer of the first and second metal parts was as follows: The electrode was fixed with a fixture and placed on a universal testing machine. The material portions at both ends of the electrode were clamped, a pull-out force was applied to the electrode, and the pull-out force was continuously increased. The state of the electrode was observed until the composite interface failed, and the data was recorded. The flange bearing pressure testing method was as follows: The electrode was fixed with a fixture and placed on a universal testing machine. Pressure was applied to the flange surface of the electrode, the state of the electrode was observed, and the data was recorded. The Z-axis thrust resistance testing method for the top cover assembly was as follows: The top cover was fixed with a tooling fixture and placed on a universal testing machine. Continuously increasing pressure was applied to the welded part of the top cover electrode, the state of the top cover was observed, and the data was recorded until the welded part failed. The results are shown in Table 1.

[0110] Table 1 Comparison of test results in different embodiments and comparative examples.

[0111]

[0112]

[0113] As shown in Table 1, compared to Comparative Example 1, the poles in Examples 1-7 of this application can withstand greater pull-out forces, the resulting top cover has greater Z-axis thrust resistance, and the resistance and flange bearing capacity of the poles are also maintained at a high level, resulting in superior overall performance. Test results of the pole and top cover assemblies in Examples 1-7 and Comparative Example 1 show that by controlling the ratio within the range of 0.4-1.55, better overall performance of the pole and top cover assemblies can be ensured, achieving a balance between low resistance, high pull-out force, high bearing capacity, and high Z-axis thrust resistance.

[0114] In comparison, the overall performance of the pole post and top cover assembly in Embodiments 1-4 of this application is better than that in Embodiments 5-7, indicating that when H1 / H2 is in the range of 0.5-1.0, the relevant performance of the pole post and top cover assembly can be further improved.

[0115] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. An electrode post, characterized in that, Includes a first metal component and a second metal component stacked along a first direction; The first metal part is provided with a first protrusion that protrudes along the first direction, and the second metal part is provided with a first recess, wherein the first protrusion is fitted into the first recess. The first metal part has a maximum thickness of H1 at the first protrusion in the first direction, and the second metal part has a corresponding thickness of H2 at the maximum thickness of the first metal part in the first direction, satisfying: 0.25≤H1 / H2≤1.55; The first metal part and the second metal part are made of different materials.

2. The pole post according to claim 1, characterized in that, 0.4≤H1 / H2≤1.

55.

3. The pole post according to claim 2, characterized in that, 0.5≤H1 / H2≤1.

0.

4. The pole post according to claim 1, characterized in that, The first metal part has a reverse wrapping structure on its periphery, and a second recess is formed between the reverse wrapping structure and the first protrusion. The second metal part has a second protrusion on its periphery; The second protrusion is fitted into the second recess and is engaged with the first metal part by the reverse wrapping structure and the first protrusion.

5. The electrode post according to claim 4, characterized in that, The second metal part has a maximum width of W1 in the second direction, the first protrusion has a thickness of H3 in the first direction, the area in the first protrusion where H3 / H1≥0.6 forms a first protrusion interval, and the first protrusion interval has a maximum width of W2 in the second direction, satisfying: 0<W2 / W1≤0.7; The second direction and the first direction are perpendicular to each other.

6. The electrode post according to claim 5, characterized in that, The reverse-wrapping structure has an arc-shaped protrusion that bulges along the second direction, and the second metal part forms an arc-shaped recess corresponding to the arc-shaped protrusion.

7. The pole post according to claim 6, characterized in that, The maximum width of the arc-shaped protrusion in the second direction is W3, which satisfies 0 < W3 / W1 ≤ 0.

3.

8. The pole post according to claim 4, characterized in that, The first metal part has a protrusion on its periphery that protrudes beyond the outer periphery of the first metal part.

9. The pole post according to claim 8, characterized in that, The maximum thickness of the first metal part in the reverse-wrapping structure along the first direction is greater than the thickness of the protrusion along the first direction.

10. The pole post according to claim 9, characterized in that, The thickness of the protrusion along the first direction is H4, and the maximum thickness of the first metal part at the reverse wrapping structure along the first direction is H5, satisfying that 0 < H5 - H4 ≤ 0.1 mm.

11. The pole post according to claim 8, characterized in that, The second metal part is provided with a first step structure and a second step structure; The second step structure is disposed at the end of the second metal part away from the first metal part, and the first step structure is disposed between the protrusion and the second step structure.

12. The pole post according to any one of claims 1-11, characterized in that, The first metal part is made of copper, and the second metal part is made of aluminum.

13. A top cover assembly, characterized in that, Includes the pole as described in any one of claims 1-12.

14. The top cover assembly according to claim 13, characterized in that, It also includes a cover plate; The cover plate is provided with a through hole, and the pole is inserted through the through hole into the cover plate.

15. The top cover assembly according to claim 14, characterized in that, It also includes insulating components and sealing rings; The sealing ring is fitted onto the pole post, and the pole post is in sealed contact with the cover plate through the sealing ring. The pole post is also kept insulated from the cover plate through the insulating component.

16. The top cover assembly according to claim 14, characterized in that, It also includes a terminal clamping block, through which the pole is pressed onto the cover plate.

17. A battery cell, characterized in that, It includes a housing, a core package, and a top cover assembly as described in any one of claims 13-16, wherein the core package is disposed within the housing, and the top cover assembly is fastened to an open end of the housing.

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