Cover plate assembly and cylindrical battery cell

Abstract

The utility model discloses a cover plate assembly and a cylindrical cell, the cover plate assembly comprises a pole, an upper plastic part, a top cover, a lower plastic part and a connecting part, the connecting part comprises a first connecting piece, a second connecting piece and a third connecting piece, two connecting ends of the first connecting piece are respectively arranged on a group of opposite surfaces of the pole and the upper plastic piece so as to connect the pole and the upper plastic piece, and two connecting ends of the second connecting piece are respectively arranged on a group of opposite surfaces of the upper plastic piece and the top cover so as to connect the upper plastic piece and the top cover; and two connecting ends of the third connecting piece are respectively arranged on a group of opposite surfaces of the top cover and the lower plastic piece so as to connect the top cover and the lower plastic piece. According to the utility model, the energy density of the battery cell can be improved on the basis of ensuring that the cover plate assembly is light in weight; and all parts can be effectively positioned, so that the production efficiency of the cover plate assembly is improved, the strength is ensured, and the safety risk is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of cylindrical battery cell production, and particularly relates to a cover plate assembly and a cylindrical battery cell. Background Art

[0002] The cover plate assembly of a battery cell generally includes a pole column, an upper plastic part, a top cover plate, a lower plastic part, a sealing ring, a current collector plate, rivets, etc., and the above components are press-riveted and fixed by rivets passing through them. In a conventional structure, the pole column, the upper plastic part, the top cover plate and the lower plastic part among the above components are positioned by two rivets. This structure has more components, relatively complex assembly, and will increase the weight of the entire cover plate assembly, thereby reducing the energy density of the battery cell. Although some technologies adopt a single-rivet structure to solve the problems of the cover plate weight and the energy density of the battery cell, such as the "Battery Cover Plate Assembly and Cylindrical Battery" disclosed in the Chinese utility model patent with the authorization announcement number CN218769803U. However, in these technologies, only the outer shapes of the pole column and the upper plastic part are used to relatively position the pole column and the upper plastic part. In order to position the upper plastic part and the top cover plate, a counterbore is machined on the top cover plate, and the upper plastic part sinks into the counterbore and is positioned by its outer shape, resulting in a certain degree of reduction in the strength at this position, thereby increasing the safety risk of the battery cell. Summary of the Utility Model

[0003] In view of this, the utility model provides a cover plate assembly and a cylindrical battery cell, which can solve the technical problems of poor positioning effect, low strength and high safety risk of the battery cell existing in the existing cover plate assembly structure on the basis of ensuring light weight and large energy density of the battery cell.

[0004] To achieve the above technical purpose, the utility model adopts the following technical solutions:

[0005] In a first aspect, the utility model provides a cover plate assembly, including a pole column, an upper plastic part, a top cover, a lower plastic part and a connecting component. Among them, the connecting component includes a first connecting piece, a second connecting piece and a third connecting piece. Two connecting ends of the first connecting piece are respectively arranged on a group of opposite surfaces of the pole column and the upper plastic part to connect the pole column and the upper plastic part. Two connecting ends of the second connecting piece are respectively arranged on a group of opposite surfaces of the upper plastic part and the top cover to connect the upper plastic part and the top cover. Two connecting ends of the third connecting piece are respectively arranged on a group of opposite surfaces of the top cover and the lower plastic part to connect the top cover and the lower plastic part.

[0006] In some embodiments, the first connecting piece includes a groove and a boss that are adapted to each other, and the groove and the boss respectively constitute two connecting ends of the first connecting piece.

[0007] In some embodiments, on both sides of the bottom of the terminal post, depressions are formed from the side edges towards the center of the terminal post and from the bottom surface towards the top surface of the terminal post to form the grooves.

[0008] Among them, the grooves are at a certain distance from the center and the upper surface of the terminal post.

[0009] In some embodiments, at the position corresponding to the grooves on the top of the upper plastic part, a boss is formed by extending from the top surface of the upper plastic part away from the upper plastic part.

[0010] In some embodiments, the second connecting member includes a first blind hole and a first positioning post that are adapted to each other, and the first blind hole and the first positioning post constitute two connecting ends of the second connecting member.

[0011] In some embodiments, the first positioning post is arranged at the bottom of the upper plastic part and on both sides of the central hole of the upper plastic part, and the first blind hole is arranged at the position corresponding to the first positioning post on the upper surface of the top cover.

[0012] In some embodiments, the third connecting member includes a second blind hole and a second positioning post that are adapted to each other, and the second blind hole and the second positioning post constitute two connecting ends of the third connecting member.

[0013] In some embodiments, the second positioning post is arranged at the top of the lower plastic part and on both sides of the central hole of the lower plastic part, and the second blind hole is arranged at the position corresponding to the second positioning post on the lower surface of the top cover.

[0014] In some embodiments, the unilateral mating clearances between the two connecting ends of the first connecting member, the two connecting ends of the second connecting member, and the two connecting ends of the third connecting member are all 0.03 - 0.08 mm.

[0015] On the other hand, the present utility model provides a cylindrical battery cell, and the cylindrical battery cell includes the cover plate assembly provided in the first aspect of the present utility model.

[0016] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0017] A cover plate assembly and a cylindrical battery cell provided by the present utility model. The connection between the upper plastic part and the top cover is no longer achieved by sinking the upper plastic part into the sinking groove of the top cover. Instead, a second connecting member is provided on a set of opposing surfaces of the upper plastic part and the top cover, and the upper plastic part and the top cover are connected through two connecting ends of the second connecting member. This method does not require machining a sinking groove on the top cover, can ensure the strength of the top cover, and reduce the safety risk of the battery cell. Moreover, effective positioning can be achieved between the pole column and the upper plastic part, between the upper plastic part and the top cover, and between the top cover and the lower plastic part through the first connecting member, the second connecting member, and the third connecting member, ensuring that each component is assembled in the correct position and improving the production efficiency of the cover plate assembly. Brief Description of the Drawings

[0018] Figure 1 is an exploded view of the cover plate assembly described in this embodiment;

[0019] Figure 2 is a cross-sectional view of the cover plate assembly described in this embodiment;

[0020] Figure 3 is a schematic structural view of the bottom of the pole column described in this embodiment;

[0021] Figure 4 is a schematic structural view of the top of the upper plastic part described in this embodiment;

[0022] Figure 5 is a schematic structural view of the bottom of the upper plastic part described in this embodiment;

[0023] Figure 6 is a schematic structural view of the top of the top cover described in this embodiment;

[0024] Figure 7 is a schematic structural view of the bottom of the top cover described in this embodiment;

[0025] Figure 8 is a schematic structural view of the top of the lower plastic part described in this embodiment.

[0026] 1. Pole column, 2. Upper plastic part, 3. Top cover, 4. Lower plastic part, 5. Connecting component, 51. First connecting member, 511. Groove, 512. Protrusion, 52. Second connecting member, 521. First blind hole, 522. First positioning post, 53. Third connecting member, 531. Second blind hole, 532. Second positioning post; 6. Current collector plate, 7. Sealing ring, 8. Rivet. Detailed Embodiment

[0027] In order to make the objectives, technical solutions, and advantages of the present utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0028] The connection method between the upper plastic part and the top cover of the existing battery cell cover plate assembly is to process a counterbore on the top cover and sink the upper plastic part into the counterbore. This method will reduce the strength of the top cover at the counterbore, resulting in an increased safety risk for the battery cell. To address this technical problem, the present utility model proposes a cover plate assembly and a cylindrical battery cell, which solve the technical problem of reduced strength of the top cover by changing the connection method between the upper plastic part and the top cover.

[0029] As Figure 1 and Figure 2 shown, this embodiment provides a cover plate assembly applicable to a cylindrical battery cell, including a terminal post 1, an upper plastic part 2, a top cover 3, a lower plastic part 4, and a connecting component 5. The connecting component 5 includes a first connecting piece 51, a second connecting piece 52, and a third connecting piece 53. Two connecting ends of the first connecting piece 51 are respectively arranged on a set of opposite surfaces of the terminal post 1 and the upper plastic part 2 to connect the terminal post 1 and the upper plastic part 2. Two connecting ends of the second connecting piece 52 are respectively arranged on a set of opposite surfaces of the upper plastic part 2 and the top cover 3 to connect the upper plastic part 2 and the top cover 3. Two connecting ends of the third connecting piece 53 are respectively arranged on a set of opposite surfaces of the top cover 3 and the lower plastic part 4 to connect the top cover 3 and the lower plastic part 4.

[0030] In this embodiment, the terminal post 1, the upper plastic part 2, the top cover 3, and the lower plastic part 4 are respectively connected through the first connecting piece 51, the second connecting piece 52, and the third connecting piece 53, which can be effectively positioned to prevent the components from being installed in the wrong direction. Through the positioning design among the above-mentioned multiple components, after the cover plate assembly and the battery cell are manufactured, it can prevent the terminal post 1 from twisting along the axial direction of the battery cell, avoiding the safety risk caused by the rotation of the terminal post 1 after the battery cells are grouped.

[0031] Thus, it is ensured that the terminal post 1, the upper plastic part 2, the top cover 3, and the lower plastic part 4 are assembled in the correct positions, improving the production efficiency of the cover plate assembly; and the upper plastic part 2 and the top cover 3 are positioned and connected through the second connecting piece 52, and there is no longer a need to open a counterbore on the top cover 3 to thin it, thus avoiding the influence on the strength of the top cover 3. Therefore, this embodiment can ensure the strength of the top cover 3, thereby reducing the safety risk of the battery cell.

[0032] In one of the embodiments, as Figure 3 and Figure 4 shown, the first connecting piece 51 includes a groove 511 and a boss 512 that are adapted to each other. The groove 511 and the boss 512 respectively constitute the two connecting ends of the first connecting piece 51, and the terminal post 1 and the upper plastic part 2 are positioned and connected through the clamping of the groove 511 and the boss 512.

[0033] In one embodiment, on both sides of the bottom of the terminal post 1, depressions are formed from the side edges towards the center of the terminal post and from the bottom surface towards the top surface of the terminal post 1 to form the groove 511, and the groove 511 maintains a certain distance from the center and the upper surface of the terminal post 1; at a position corresponding to the groove 511 on the top of the upper plastic part 2, a boss 512 is formed by extending from the top surface of the upper plastic part 2 away from the upper plastic part 2. That is, in this embodiment, the groove 511 is formed on the terminal post 1 and the boss 512 is provided on the upper plastic part 2. Since the material of the terminal post 1 is metal and the material of the upper plastic part 2 is plastic, this design method is beneficial to reducing the weight of the cover plate assembly and improving the energy density of the battery cell.

[0034] In one embodiment, as Figure 5 and Figure 6 shown, the second connecting member 52 includes a first blind hole 521 and a first positioning post 522 that are adapted to each other, and the first blind hole 521 and the first positioning post 522 constitute two connecting ends of the second connecting member 52; the first positioning post 522 is disposed at the bottom of the upper plastic part 2 and on both sides of the central hole of the upper plastic part 2, and the first blind hole 521 is disposed at a position on the upper surface of the top cover 3 corresponding to the first positioning post 522.

[0035] That is, in this embodiment, the first blind hole 521 is formed on the top cover 3, and the first positioning post 522 is disposed at the bottom of the upper plastic part 2. Since the material of the top cover 3 is metal and the material of the upper plastic part 2 is plastic, this design method is beneficial to reducing the weight of the cover plate assembly and improving the energy density of the battery cell.

[0036] In one embodiment, as Figure 7 and Figure 8 shown, the third connecting member 53 includes a second blind hole 531 and a second positioning post 532 that are adapted to each other, and the second blind hole 531 and the second positioning post 532 constitute two connecting ends of the third connecting member 53; the second positioning post 532 is disposed at the top of the lower plastic part 4 and on both sides of the central hole of the lower plastic part 4, and the second blind hole 531 is disposed at a position on the lower surface of the top cover 3 corresponding to the second positioning post 532.

[0037] That is, in this embodiment, the second blind hole 531 is formed at the bottom of the top cover 3, and the second positioning post 532 is disposed at the top of the lower plastic part 4. Since the material of the top cover 3 is metal and the material of the lower plastic part 4 is plastic, this design method is beneficial to reducing the weight of the cover plate assembly and improving the energy density of the battery cell.

[0038] In one embodiment, the unilateral mating clearance between the two connecting ends of the first connecting member 51, the two connecting ends of the second connecting member 52, and the two connecting ends of the third connecting member 53 is 0.03 - 0.08 mm, preferably 0.05 mm.

[0039] In one embodiment, this embodiment further includes a current collecting plate 6 connected to the bottom of the lower plastic part 4. A sealing ring 7 is also provided between the current collecting plate 6 and the lower plastic part 4. The current collecting plate 6, the sealing ring 7, and the lower plastic part 4 are press-riveted and connected by rivets 8.

[0040] It should be noted that between the lower plastic part 4 and the top cover 3 of this embodiment, there is a liquid injection structure or an explosion-proof valve structure on the top cover 3. Some designs have both of these two structures, and there will also be corresponding structures at the corresponding positions of the lower plastic part 4 to match the liquid injection structure and the explosion-proof structure. The positioning between these two components needs to be designed as an asymmetric structure, so that the lower plastic part 4 and the top cover 3 can be assembled in the correct position during production and assembly.

[0041] In a second aspect, a cylindrical battery cell of this embodiment includes the cover plate assembly described in the first aspect of the present utility model.

[0042] It can be understood that the shapes and numbers of the groove 511, the boss 512, the first blind hole 521, the first positioning post 522, the second blind hole 531, and the second positioning post 532 in this embodiment can be flexibly designed according to actual needs.

[0043] In summary, a cover plate assembly and a cylindrical battery cell provided by the present utility model reduce the amount of metal parts and increase the amount of plastic parts in their structures. By this method, the weight of the cover plate assembly can be ensured to be lighter, which can improve the energy density of the battery cell; and effective positioning can be achieved between each component, improving the production efficiency of the cover plate assembly and ensuring the strength, reducing the safety risk.

[0044] The specific embodiments of the present utility model described above do not constitute a limitation to the protection scope of the present utility model. Any other corresponding changes and deformations made according to the technical concept of the present utility model should be included in the protection scope of the claims of the present utility model.

Claims

1. A cover plate assembly, characterized in that: It includes pole, upper plastic part, top cover, lower plastic part and connecting parts, among which: The connecting component includes a first connecting member, a second connecting member and a third connecting member, the two connecting ends of the first connecting member are respectively arranged on a group of opposite surfaces of the pole and the upper plastic member to connect the pole and the upper plastic member, the two connecting ends of the second connecting member are respectively arranged on a group of opposite surfaces of the upper plastic member and the top cover to connect the upper plastic member and the top cover, and the two connecting ends of the third connecting member are respectively arranged on a group of opposite surfaces of the top cover and the lower plastic member to connect the top cover and the lower plastic member.

2. The cover plate assembly according to claim 1, characterized in that: The first connecting member comprises a matching groove and a boss, and the groove and the boss respectively constitute two connecting ends of the first connecting member.

3. The cover plate assembly according to claim 2, characterized in that: The two sides of the bottom of the pole are recessed from the side edges toward the center of the pole and from the bottom surface toward the top surface of the pole to form the groove. Wherein, the groove maintains a certain distance from the center and the upper surface of the pole.

4. The cover plate assembly according to claim 3, characterized in that: The position of the top of the upper plastic part corresponding to the groove extends from the top surface of the upper plastic part in a direction away from the upper plastic part to form the boss.

5. The cover plate assembly according to claim 1, characterized in that: The second connecting member includes a first blind hole and a first positioning column that match each other, and the first blind hole and the first positioning column constitute two connecting ends of the second connecting member.

6. The cover plate assembly according to claim 5, characterized in that: The first positioning column is arranged at the bottom of the upper plastic part and located at both sides of the central hole of the upper plastic part, and the first blind hole is arranged at a position on the upper surface of the top cover corresponding to the first positioning column.

7. The cover plate assembly according to claim 1, characterized in that: The third connecting member comprises a second blind hole and a second positioning column adapted to each other, and the second blind hole and the second positioning column constitute two connecting ends of the third connecting member.

8. The cover plate assembly according to claim 7, characterized in that: The second positioning column is arranged on the top of the lower plastic part and located on both sides of the central hole of the lower plastic part, and the second blind hole is arranged on the lower surface of the top cover at a position corresponding to the second positioning column.

9. The cover plate assembly according to claim 1, characterized in that: The single-side fitting clearances between the two connecting ends of the first connecting member, the two connecting ends of the second connecting member, and the two connecting ends of the third connecting member are all 0.03-0.08 mm.

10. A cylindrical battery cell, characterized in that: The cylindrical battery cell comprises the cover plate assembly according to any one of claims 1-9.

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