Battery cover plate assembly and cylindrical battery thereof

Abstract

The utility model relates to the technical field of lithium batteries, and discloses a battery cover plate assembly and a cylindrical battery thereof. The battery cover plate assembly comprises a separation piece and an end cover, a positive pole is arranged between the separation piece and the end cover, a mounting hole is formed in the separation piece, and a clearance hole is formed in the end cover; the bottom end of the positive pole is clamped in the mounting hole, and the top end of the positive pole penetrates through the clearance hole and extends to the upper part of the end cover; an annular blocking part integrally formed with the positive pole is arranged on the outer diameter of the positive pole, an insulating sealant layer is arranged on the upper end face of the annular blocking part, and the end cover is fixedly connected with the positive pole in an insulating and sealing manner through the insulating sealant layer. According to the battery cover plate assembly, the liquid leakage risk caused by false riveting of a traditional riveting structure is effectively prevented; and on the other hand, the sealing performance of the structure is extremely stable in the high-temperature, high-humidity and high-low temperature alternating environment, and the risk of liquid leakage does not exist.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery technology, specifically to a battery cover assembly and its cylindrical battery. Background Technology

[0002] Cylindrical batteries are characterized by high capacity, long cycle life, and a wide operating temperature range. With the development of the new energy industry, higher demands are being placed on battery energy density, cycle life, safety, and reliability. In existing technologies, the terminals and cover plate assemblies of cylindrical batteries are mostly sealed and fixed using riveting, i.e., the terminals are riveted to the cover plate after the sealing ring is compressed. However, there is a certain probability of incomplete riveting during the riveting process, leading to the risk of electrolyte leakage. Furthermore, the sealing performance of riveted structures is extremely unstable under high temperature, high humidity, and alternating high and low temperature environments, also posing a risk of leakage.

[0003] Therefore, there is an urgent need for a battery cover assembly and its cylindrical battery to solve the above problems. Utility Model Content

[0004] Based on the above, the purpose of this utility model is to provide a battery cover assembly and its cylindrical battery to solve the problem of leakage risk in the riveted sealing structure between the terminal post and the cover assembly of the existing cylindrical battery.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] This utility model provides a battery cover assembly, including an insulating sheet and an end cap. A positive electrode post is installed between the insulating sheet and the end cap. The insulating sheet has a mounting hole, and the end cap has a clearance hole. The bottom end of the positive electrode post is engaged in the mounting hole, and its top end extends through the clearance hole to the top of the end cap.

[0007] The outer diameter of the positive electrode post is provided with an annular retaining portion integrally formed therewith. The upper end face of the annular retaining portion is provided with an insulating and sealing adhesive layer. The end cap is fixedly connected to the positive electrode post through the insulating and sealing adhesive layer. The diameter of the vent hole is larger than the diameter of the positive electrode post.

[0008] As an optional technical solution for battery cover assembly, the bottom edge of the positive electrode post has a chamfered structure, and an annular snap-fit ​​groove is provided between the annular retaining part and the bottom end of the positive electrode post. The positive electrode post is snapped into the mounting hole through the annular snap-fit ​​groove.

[0009] As an optional technical solution for battery cover assembly, an annular groove is provided between the annular retaining portion and the top of the positive electrode post, and UV-curable adhesive is provided in the annular groove.

[0010] As an optional technical solution for battery cover assembly, the diameter of the UV-curable adhesive is larger than the diameter of the positive electrode post, and the bottom surface of the end cap is provided with a clearance position around the clearance hole.

[0011] As an optional technical solution for battery cover assembly, the isolation plate is provided with an explosion-proof valve, and the end cover is equipped with a protective plate coaxial with the explosion-proof valve, and the protective plate is provided with a pressure relief hole.

[0012] As an optional technical solution for battery cover assembly, the end cover and the separator are respectively provided with coaxial liquid injection holes, and the liquid injection holes of the end cover are sealed with sealing caps.

[0013] As an optional technical solution for battery cover assembly, the upper end face of the separator is provided with a positioning post, and the bottom surface of the end cover is provided with a positioning hole that matches the positioning post.

[0014] On the other hand, this utility model also provides a cylindrical battery, including a housing, a battery cell, and the battery cover assembly described above. The bottom of the circumferential edge of the end cover is provided with an annular recess, which is snapped into the upper opening of the housing. The end cover is welded to the housing. The battery cell is encapsulated inside the housing.

[0015] As an alternative technical solution for cylindrical batteries, a busbar is connected to the bottom end of the positive electrode post, the positive electrode tab of the battery cell is connected to the busbar, and the negative electrode tab of the battery cell is connected to the casing.

[0016] The beneficial effects of this utility model are as follows:

[0017] The present invention provides a battery cover assembly including a separator and an end cap, wherein a positive electrode post is installed between the separator and the end cap, the separator has a mounting hole, and the end cap has a clearance hole; the bottom end of the positive electrode post is engaged in the mounting hole, and its top end extends through the clearance hole to the top of the end cap; an annular retaining part integrally formed therewith is provided on the outer diameter of the positive electrode post, and an insulating sealing adhesive layer is provided on the upper end surface of the annular retaining part; the end cap is fixedly connected to the positive electrode post through the insulating sealing adhesive layer.

[0018] In the above structure, because the annular retaining part is provided with an insulating sealant layer, when the end cap and the separator are assembled, the upper surface of the insulating sealant layer will fuse and seal with the bottom surface of the end cap, and the bottom surface of the insulating sealant layer will fuse and seal with the top surface of the annular retaining part. This forms a strong insulating and sealing structure between the positive electrode post and the end cap, effectively preventing the risk of leakage caused by loose riveting in traditional riveting structures. On the other hand, because the insulating sealant layer has strong weather resistance and chemical corrosion resistance, the sealing performance of this structure is extremely stable even in high temperature, high humidity and alternating high and low temperature environments, and there is no risk of leakage. Attached Figure Description

[0019] Figure 1 This is an exploded view of the battery cover assembly in Embodiment 1 of this utility model from a first perspective.

[0020] Figure 2 This is an exploded view of the battery cover assembly in Embodiment 1 of this utility model from a second perspective;

[0021] Figure 3 This is a cross-sectional schematic diagram of the battery cover assembly in Embodiment 1 of this utility model;

[0022] Figure 4 This is a cross-sectional schematic diagram of the positive electrode post in Embodiment 1 of this utility model;

[0023] Figure 5 This is a schematic diagram of the overall structure of the cylindrical battery in Embodiment 2 of this utility model;

[0024] Figure 6 This is an exploded view of the cylindrical battery in Embodiment 2 of this utility model.

[0025] In the picture:

[0026] 1. End cap; 10. Clearance hole; 101. Clearance position; 11. Protective plate; 110. Pressure relief hole; 12. Injection hole; 13. Sealing cap; 14. Positioning hole; 15. Annular countersunk platform;

[0027] 2. Isolation plate; 20. Mounting hole; 21. Explosion-proof valve; 22. Positioning post;

[0028] 3. Positive terminal post; 30. Annular retaining part; 31. Insulating sealant layer; 32. Annular snap-fit ​​groove; 33. Annular groove; 34. UV-cured adhesive; 35. Busbar;

[0029] 4. Shell;

[0030] 5. Battery cell; 50. Positive electrode tab. Detailed Implementation

[0031] 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 merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0032] 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.

[0033] 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.

[0034] In the description of this embodiment, terms such as "upper," "lower," "left," and "right" are based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of description and simplification of operation, and are not intended to 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.

[0035] In the description of this utility model, unless otherwise stated, "a plurality of" means two or more. Furthermore, the terms "first" and "second" are used merely for descriptive distinction and have no specific meaning.

[0036] Example 1

[0037] like Figure 1-4As shown, this utility model provides a battery cover assembly, which includes an insulating sheet 2 and an end cap 1. A positive electrode post 3 is installed between the insulating sheet 2 and the end cap 1. The insulating sheet 2 has a mounting hole 20, and the end cap 1 has a clearance hole 10. The bottom end of the positive electrode post 3 is engaged in the mounting hole 20, and its top end extends through the clearance hole 10 to the top of the end cap 1. An annular retaining portion 30 is integrally formed on the outer diameter of the positive electrode post 3. An insulating sealing adhesive layer 31 is provided on the upper end surface of the annular retaining portion 30. The end cap 1 is insulated and sealed to the positive electrode post 3 through the insulating sealing adhesive layer 31. The diameter of the clearance hole 10 is larger than the diameter of the positive electrode post 3.

[0038] The battery cover assembly provided by this utility model provides an insulating and sealing adhesive layer 31 on the annular retaining portion 30. When the end cover 1 and the separator 2 are assembled, the upper surface of the insulating and sealing adhesive layer 31 will be fused and sealed with the bottom surface of the end cover 1, and the bottom surface of the insulating and sealing adhesive layer 31 will be fused and sealed with the top surface of the annular retaining portion 30. This forms a strong insulating and sealing structure between the positive electrode post 3 and the end cover 1, effectively preventing the risk of leakage caused by loose riveting in traditional riveting structures. On the other hand, because the insulating and sealing adhesive layer 31 has strong weather resistance and chemical corrosion resistance, the sealing performance of this structure is extremely stable in high temperature, high humidity and alternating high and low temperature environments, and there is no risk of leakage.

[0039] Specifically, such as Figure 4 As shown, the positive electrode post 3 and the annular retaining part 30 are integrally molded structures. This structure makes the connection stability between the positive electrode post 3 and the annular retaining part 30 stronger, effectively avoiding leakage between the annular retaining part 30 and the positive electrode post 3. In order to further improve the sealing stability between the insulating sealant and the positive electrode post 3, an annular groove 33 is provided between the annular retaining part 30 and the top of the positive electrode post 3. The annular groove 33 is coated with UV-curable adhesive 34 (such as... Figure 1 or Figure 2 or Figure 3 (As shown) The diameter of the UV-curable adhesive 34 is larger than the diameter of the positive electrode post 3. That is to say, after the UV-curable adhesive 34 is applied into the annular groove 33, its outer diameter is larger than the maximum outer diameter of the positive electrode post 3. In this way, the UV-curable adhesive 34 can form a firm sealing connection with the annular groove 33 on the one hand, and can effectively seal and fuse with the upper end face of the insulating sealant layer 31 on the other hand. Under this structure, the sealing performance between the insulating sealant layer 31 and the positive electrode post 3 is further improved. Even if the battery cover assembly is used in high temperature, high humidity and alternating high and low temperature environments, its sealing performance is extremely stable. It will not cause leakage due to the shrinkage or expansion of the insulating sealant layer 31 caused by temperature difference, resulting in gaps between it and the positive electrode post 3. This effectively increases the stability and service life of the battery cover assembly.

[0040] Furthermore, such as Figure 2 As shown, the bottom surface of the end cap 1 is provided with a clearance position 101 around the clearance hole 10. After the end cap 1 and the separator 2 are sealed, the UV-curable adhesive 34 is placed in the clearance position 101. Under this structure, the insulating sealant layer 31 can have sufficient spacing to bond and fuse with the bottom of the end cap 1, which further improves the sealing performance and stability between the end cap 1 and the positive electrode post 3. Since the diameter of the clearance hole 10 is larger than the diameter of the positive electrode post 3, when the top of the positive electrode post 3 passes through the clearance hole 10 and extends above it, a certain safety distance will be formed between the positive electrode post 3 and the end cap 1, preventing electrical contact between the positive electrode post 3 and the end cap 1, and effectively improving the safety of the battery cover assembly.

[0041] In this embodiment, as Figure 3 and Figure 4 As shown, the bottom edge of the positive electrode post 3 has a chamfered structure, and an annular retaining part 30 and the bottom end of the positive electrode post 3 are provided with an annular locking groove 32. When the bottom end of the positive electrode post 3 passes through the mounting hole 20, the chamfered shape of its bottom end can make the bottom end of the positive electrode post 3 pass through the mounting hole 20 more linearly, and make the annular locking groove 32 lock onto the circumferential side wall (isolation piece 2) of the mounting hole 20. Under this structure, the assembly efficiency of the positive electrode post 3 and the isolation piece 2 is accelerated and the firmness and stability between the two are improved.

[0042] Furthermore, such as Figure 1 As shown, the isolation plate 2 is provided with an explosion-proof valve 21 and a liquid injection hole 12 on the left and right sides of the mounting hole 20. The end cap 1 is provided with a through hole and a liquid injection hole 12 on the left and right sides of the vent hole 10. A protective plate 11 is encapsulated on the through hole, and a sealing cap 13 is encapsulated on the liquid injection hole 12 of the end cap 1. The explosion-proof valve 21, the through hole, and the protective plate 11 are arranged coaxially, and a pressure relief hole 110 is opened on the protective plate 11. When this battery cover assembly is applied to the finished battery, if the temperature or pressure inside the battery reaches a certain threshold, the explosion-proof valve 21 will rupture, allowing the battery to communicate with the outside through the pressure relief hole 110, effectively preventing the battery from causing safety hazards due to high temperature and high pressure. The liquid injection hole 12 on the end cap 1 and the isolation plate 2 are arranged coaxially. In this embodiment, the sealing cap 13 is an aluminum nail structure. The sealing cap 13 and the end cap 1 can be connected by adhesive or welding, so that the sealing cap 13 and the liquid injection hole 12 form an absolute sealing structure to prevent electrolyte leakage.

[0043] Furthermore, such as Figure 1 and Figure 2As shown, the upper end face of the separator 2 is provided with a positioning post 22, and the bottom surface of the end cover 1 is provided with a positioning hole 14 that matches the positioning post 22. The number of positioning posts 22 and positioning holes 14 is not less than two. This enables the end cover 1 and the separator 2 to be quickly and accurately assembled, and enables the through hole to be quickly and coaxially aligned with the explosion-proof valve 21 and the two liquid injection holes 12, thereby improving the assembly efficiency and assembly accuracy of the battery cover assembly.

[0044] Example 2

[0045] like Figure 5 and Figure 6 As shown, this utility model also provides a cylindrical battery, which includes a casing 4, a cell 5, and the battery cover assembly described in Embodiment 1. An annular recess 15 is provided at the bottom of the circumferential edge of the end cap 1, which engages with the upper opening of the casing 4, enabling rapid positioning and assembly between the battery cover assembly and the casing 4. The end cap 1 and the casing 4 are laser-welded together, which enhances the connection stability between the battery cover assembly and the casing 4 and prevents the risk of leakage. The cell 5 is encapsulated within the casing 4, and a busbar 35 is connected to the bottom of the positive electrode post 3. The positive electrode tab 50 of the cell 5 is connected to the busbar 35, while its negative electrode tab is connected to the casing 4. Because the positive electrode post 3 of the battery cover assembly is provided with an insulating sealant layer 31 and a UV-curable adhesive 34, the operating environment and service life of the cylindrical battery are further improved, resulting in greater stability.

[0046] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some changes or modifications to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes, and modifications made to the above embodiments based on the present utility model without departing from the scope of the present utility model shall fall within the scope of the present utility model.

Claims

1. A battery cover assembly, comprising a separator and an end cap, wherein a positive electrode post is disposed between the separator and the end cap, characterized in that, The insulating sheet has mounting holes, and the end cap has clearance holes; the bottom end of the positive electrode post is engaged in the mounting holes, and its top end extends through the clearance holes to the top of the end cap. The outer diameter of the positive electrode post is provided with an annular retaining part integrally formed therewith. The upper end face of the annular retaining part is provided with an insulating and sealing adhesive layer. The end cap is fixedly connected to the positive electrode post through the insulating and sealing adhesive layer. The diameter of the vent hole is larger than the diameter of the positive electrode post.

2. The battery cover assembly according to claim 1, characterized in that, The bottom edge of the positive electrode post has a chamfered structure, and an annular locking groove is provided between the annular retaining part and the bottom end of the positive electrode post. The positive electrode post is locked into the mounting hole through the annular locking groove.

3. The battery cover assembly according to claim 1, characterized in that, An annular groove is provided between the annular stop portion and the top of the positive electrode post, and UV-curable adhesive is provided in the annular groove.

4. A battery cover assembly according to claim 3, characterized in that, The diameter of the UV-curable adhesive is larger than the diameter of the positive electrode post, and the bottom surface of the end cap is provided with a clearance position around the clearance hole.

5. A battery cover assembly according to claim 1, characterized in that, The isolation plate is equipped with an explosion-proof valve, and the end cap is equipped with a protective plate coaxial with the explosion-proof valve. The protective plate is equipped with a pressure relief hole.

6. A battery cover assembly according to claim 1, characterized in that, The end cap and the isolation plate are respectively provided with coaxial liquid injection holes, and the liquid injection holes of the end cap are sealed with sealing caps.

7. A battery cover assembly according to claim 1, characterized in that, The upper end face of the isolation plate is provided with a positioning post, and the bottom surface of the end cap is provided with a positioning hole that matches the positioning post.

8. A cylindrical battery, comprising a casing, a cell, and a battery cover assembly as described in any one of claims 1-7, characterized in that, The end cap has an annular recess at the bottom of its circumferential edge. The annular recess is engaged with the upper opening of the housing. The end cap is welded to the housing. The battery cell is encapsulated inside the housing.

9. A cylindrical battery according to claim 8, characterized in that, The bottom end of the positive terminal is connected to a busbar, the positive electrode tab of the battery cell is connected to the busbar, and the negative electrode tab of the battery cell is connected to the housing.

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