Thermal composite cover plate

Abstract

The thermal composite cover plate comprises a top cover and a pole assembly, a first through hole is formed in the surface of the top cover, and the top cover is provided with an outer side face and an inner side face; the pole assembly comprises an external pole and an internal pole, the external pole is attached to the outer side face of the top cover, a second through hole is formed in the surface of the external pole, and the second through hole and the first through hole are concentrically arranged; the built-in pole is provided with a sheet-shaped part and a protruding part arranged on the surface of the sheet-shaped part, the sheet-shaped part is attached to the inner side face of the top cover, the protruding part penetrates through the first through hole and the second through hole and is partially exposed outside, and the sheet-shaped part and the external pole jointly clamp the top cover so as to prevent the battery from leaking liquid. According to the technical scheme, high sealing performance is achieved, and electrolyte leakage is effectively prevented.

Description

Technical Field

[0001] This invention relates to the field of battery manufacturing technology, and in particular to a thermally composite cover plate. Background Technology

[0002] Traditional battery covers typically employ a simple assembly structure of metal terminals and a cover body, relying on a single sealing ring or adhesive layer for sealing. This design has significant shortcomings: the connection between the terminals and the cover relies primarily on mechanical pressing, which can easily create micro-gaps under long-term vibration, temperature changes, or internal pressure fluctuations; and the physical contact between components alone cannot guarantee a lasting seal. Furthermore, the sealing material is prone to aging and failure under electrolyte corrosion. These defects lead to a widespread risk of electrolyte leakage with traditional covers, affecting battery performance and potentially posing safety hazards. Especially in demanding applications such as power batteries, the leakage prevention capabilities of existing structures are insufficient to meet the requirements for long lifespan and high reliability. Summary of the Invention

[0003] The main objective of this invention is to provide a thermally composite cover plate that has high sealing performance and effectively prevents electrolyte leakage.

[0004] To achieve the above objectives, the present invention provides a thermal composite cover plate, comprising:

[0005] A top cover, wherein a first through hole is provided on the surface of the top cover, and the top cover has an outer side and an inner side;

[0006] The terminal assembly includes an external terminal and an internal terminal. The external terminal is fitted onto the outer side of the top cover, and a second through hole is formed on the surface of the external terminal, which is concentrically arranged with the first through hole. The internal terminal has a sheet-like portion and a protrusion on the surface of the sheet-like portion. The sheet-like portion is fitted onto the inner side of the top cover, and the protrusion passes through the first and second through holes and is partially exposed. The sheet-like portion and the external terminal together clamp the top cover to prevent battery leakage.

[0007] In one possible implementation, a layer of polymer material is further provided between the sheet-like portion of the built-in pole and the inner side of the top cover.

[0008] In one possible implementation, the built-in pole, polymer material layer, and top cover are passivated before being encapsulated at high temperature.

[0009] In one possible implementation, an elastic sealing ring is also provided between the external pole and the outer side of the top cover.

[0010] In one possible implementation, the elastic sealing ring is made of fluororubber.

[0011] In one possible implementation, the connection between the external electrode and the internal electrode is formed as one unit by laser welding.

[0012] In one possible implementation, a partition is also fitted onto the inner side of the top cover, and a third through hole is formed on the surface of the partition corresponding to the sheet-like portion.

[0013] The technical solution of this invention achieves superior leak-proof performance through a multi-layer sealing and reinforced structural design. A polymer material layer is placed between the plate-like part of the built-in electrode and the inner side of the top cover, and a fluororubber sealing ring is added between the external electrode and the outer side of the top cover to form a double seal. The built-in electrode assembly is passivated and then encapsulated at high temperature to form chemical bonds at the molecular level. The electrode assembly is integrally formed by laser welding to completely eliminate connection gaps. A partition with a third through hole is added to the inner side of the top cover, which fits tightly with the top cover to form multiple barriers. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the structure of an embodiment of the thermal composite cover plate of the present invention;

[0016] Figure 2 This is an exploded view of an embodiment of the thermal composite cover plate of the present invention;

[0017] Figure 3 This is a cross-sectional view of an embodiment of the thermal composite cover plate of the present invention.

[0018] Explanation of icon numbers:

[0019] 1. Top cover; 11. First through hole; 12. Outer side; 13. Inner side; 2. External pole; 21. Second through hole; 3. Internal pole; 31. Sheet-like part; 32. Protrusion; 4. Polymer material layer; 5. Elastic sealing ring; 6. Partition; 61. Third through hole.

[0020] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0022] Reference Figures 1 to 3 This invention proposes a thermal composite cover plate, including a top cover 1 and an electrode assembly. The top cover 1 has a first through hole 11 on its surface and has an outer side 12 and an inner side 13. The electrode assembly includes an external electrode 2 and an internal electrode 3. The external electrode 2 is fitted to the outer side 12 of the top cover 1 and has a second through hole 21 on its surface. The second through hole 21 and the first through hole 11 are arranged concentrically. The internal electrode 3 has a sheet-like portion 31 and a protrusion 32 on the surface of the sheet-like portion 31. The sheet-like portion 31 is fitted to the inner side 13 of the top cover 1, and the protrusion 32 passes through the first through hole 11 and the second through hole 21 and is partially exposed. The sheet-like portion 31 and the external electrode 2 together clamp the top cover 1 to prevent battery leakage.

[0023] Understandably, the top cover 1 is the battery's encapsulation cover, consisting of an outer surface 12 that contacts the external environment and an inner surface 13 that faces the inside of the battery. The terminal assembly consists of two parts: an external terminal 2 and an internal terminal 3, used for conducting electricity and preventing leakage.

[0024] The top cover 1 has a hole that extends through the inner and outer sides 12. The external electrode 2 is located on the outer side 12 of the top cover 1, close to the top cover 1, and has a second through hole 21 on its surface, aligned with the first through hole 11 of the top cover 1. The internal electrode 3 consists of two parts: a flat sheet-like part 31 that fits tightly against the inner side 13 of the top cover 1; and a protruding part 32 that protrudes from the surface of the sheet-like part 31, its shape matching the through hole. The protruding part 32 passes through the first through hole 11 of the top cover 1 and the second through hole 21 of the external electrode 2 in sequence, until it is partially exposed. The sheet-like part 31 of the internal electrode 3 and the external electrode 2 are connected by the protruding part 32, forming a cross-section similar to the letter "I". This structure clamps and seals the inner and outer sides of the top cover 1, preventing electrolyte leakage.

[0025] Reference Figures 2 to 3 In one embodiment of the present invention, a polymer material layer 4 is further provided between the sheet-like portion 31 of the built-in pole post 3 and the inner side surface 13 of the top cover 1.

[0026] Understandably, the polymer material layer 4 is used to enhance sealing. Polymer materials such as engineering plastics, rubber, or hot melt adhesives are elastic or malleable, capable of filling the microscopic gaps between the sheet-like portion 31 and the inner surface 13 of the top cover 1, blocking the electrolyte penetration path; they can also alleviate mechanical stress caused by internal battery vibration or thermal expansion and contraction, while serving as an electrical insulating layer to prevent short circuits between the terminals and the top cover 1; and the electrolyte-resistant polymer material can extend the sealing life. The top cover 1 and the sheet-like portion 31 of the built-in terminals 3 are bonded or pressed together by the polymer layer to form a more robust sealing structure.

[0027] Reference Figures 2 to 3 In one embodiment of the present invention, the built-in pole 3, the polymer material layer 4 and the top cover 1 are passivated and then encapsulated at high temperature.

[0028] Understandably, passivation treatment passesivates the surfaces of the internal electrode post 3, the polymer material layer 4, and the top cover 1, forming a dense passivation film to prevent electrolyte corrosion. The improved surface activity after passivation facilitates the formation of stronger chemical bonds with the polymer material during subsequent high-temperature packaging.

[0029] During high-temperature encapsulation, the polymer material is heated to its melting or cross-linking temperature, causing it to soften and flow, filling all microscopic gaps and forming a metal-polymer interface. The active groups on the surface of the passivation layer, such as -OH and -COOH, react with the polymer chains to form covalent bonds or hydrogen bonds. The material is then cured at high temperature, and a three-dimensional network structure is formed between molecules.

[0030] The metal-polymer interface uses chemical bonds to replace simple physical contact, significantly reducing the risk of interface delamination and greatly improving overall sealing to prevent battery leakage.

[0031] Reference Figures 2 to 3 In one embodiment of the present invention, an elastic sealing ring 5 is also provided between the external pole 2 and the outer side surface 12 of the top cover 1.

[0032] Understandably, the elastic sealing ring 5, as an external sealing unit, absorbs mechanical vibrations during battery charging and discharging or other scenarios, preventing micro-displacement between the external terminal 2 and the top cover 1; the elasticity of the elastomer can adapt to dimensional fluctuations in the metal parts caused by temperature changes; it can also prevent external moisture and dust from intruding from the assembly gap between the external terminal 2 and the top cover 1.

[0033] In addition to setting a sealing ring, the external electrode post and the top cover can also be encapsulated at high temperature using polymer materials to form a metal-polymer interface and improve sealing performance.

[0034] Reference Figures 2 to 3 In one embodiment of the present invention, the elastic sealing ring 5 is made of fluororubber.

[0035] Understandably, fluororubber, as the material for elastic sealing rings, possesses excellent high-temperature resistance, with an operating temperature range of -40℃ to 200℃, far exceeding that of ordinary rubber. This effectively copes with the localized high temperatures of the terminals during fast charging or high-rate discharging, and maintains the integrity of the seal even in the early stages of thermal runaway, buying time for safety protection. It also has excellent chemical corrosion resistance, exhibiting almost no swelling or degradation in commonly used lithium battery electrolytes, and a very low volume change rate after long-term contact. It can resist acidic byproducts such as HF produced by electrolyte decomposition, preventing the sealing ring from becoming brittle and failing. Furthermore, it has an ultra-long service life, with a high rebound rate after high-temperature compression, ensuring that the sealing pressure does not decrease over a long period.

[0036] Besides fluororubber, the sealing ring material can also be polypropylene, polytetrafluoroethylene, polyethylene, polyvinylidene fluoride, perfluoroether rubber, fluororubber, polyether ether ketone, EPDM, etc., depending on production requirements.

[0037] Reference Figures 2 to 3 In one embodiment of the present invention, the connection between the external electrode post 2 and the internal electrode post 3 is formed into one piece by laser welding.

[0038] Understandably, laser welding integrally forms the connection between the external electrode post 2 and the internal electrode post 3, which can significantly improve the mechanical strength, conductivity, and sealing of the electrode post assembly. Laser welding allows the metals to fuse directly, and the weld strength is close to that of the base material, avoiding the loosening problems that may occur with bolts or crimping. Metallurgical bonding eliminates interface resistance, improves conductivity, and reduces heat generation and energy loss. The weld completely seals the electrode post connection, eliminating the risk of electrolyte seepage from the inside. The integrated structure has no assembly gaps, avoiding electrochemical corrosion or contaminant intrusion.

[0039] Besides laser welding, mechanical riveting, ultrasonic welding, high-frequency welding, and friction welding can also be used to connect external and internal electrodes, depending on specific production requirements.

[0040] Reference Figure 2 In one embodiment of the present invention, a partition 6 is also attached to the inner side 13 of the top cover 1, and a third through hole 61 is opened on the surface of the partition 6 corresponding to the sheet-like portion 31.

[0041] Understandably, the separator 6 provides additional support to the inside of the top cover 1, resisting the expansion pressure of the battery cells inside and preventing the top cover 1 from deforming. The sheet-like part 31 is precisely positioned with the separator 6 through the third through hole 61, forming a fixed structure to prevent displacement. Furthermore, the separator 6 acts as a second physical barrier, which can delay electrolyte leakage.

[0042] The technical solution of this invention achieves superior leak-proof performance by adopting a multi-layer sealing and reinforced structural design. A polymer material layer 4 is provided between the sheet-like part 31 of the built-in electrode 3 and the inner side 13 of the top cover 1, and a fluororubber sealing ring is added between the external electrode 2 and the outer side 12 of the top cover 1 to form a double seal inside and outside. The built-in electrode 3 assembly is passivated and then encapsulated at high temperature to form chemical bonds at the molecular level. The electrode assembly is integrally formed by laser welding to completely eliminate connection gaps. A partition 6 with a third through hole 61 is added to the inner side of the top cover 1, which fits tightly with the top cover 1 to form multiple barriers.

[0043] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this application, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, they are only for the convenience of describing this application and simplifying the description, 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, the terms used to describe positional relationships in the accompanying drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0044] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A hot composite cover plate characterized by, The application relates to a battery cover and a battery pole assembly. The battery cover comprises a top cover with a first through hole on the surface, and the top cover has an outer side and an inner side. The battery pole assembly comprises an external pole and an internal pole, the external pole is arranged on the outer side of the top cover, a second through hole is arranged on the surface of the external pole, and the second through hole is concentrically arranged with the first through hole; the internal pole has a sheet-shaped part and a protruding part arranged on the surface of the sheet-shaped part, the sheet-shaped part is arranged on the inner side of the top cover, the protruding part passes through the first through hole and the second through hole and is partially exposed outside, and the sheet-shaped part and the external pole jointly clamp the top cover to prevent battery liquid leakage.

2. The hot-bonded cover plate according to claim 1, characterized in that A polymer material layer is arranged between the sheet-shaped part of the internal pole and the inner side of the top cover.

3. The hot-bonded cover plate according to claim 2, characterized in that The internal pole, the polymer material layer and the top cover are subjected to passivation treatment and high-temperature packaging.

4. The hot-bonded cover plate according to claim 1, characterized in that An elastic sealing ring is arranged between the external pole and the outer side of the top cover.

5. The hot-bonded cover plate according to claim 4, characterized in that The elastic sealing ring is made of fluorine rubber.

6. The hot-bonded cover plate according to claim 1, characterized in that The external pole and the internal pole are integrated by laser welding.

7. The thermally-composite cover sheet of claim 1, wherein, A partition plate is arranged on the inner side of the top cover, and a third through hole is arranged on the surface of the partition plate and corresponds to the sheet-shaped part.

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