A top cover assembly and a secondary battery

Abstract

The utility model belongs to battery top cover technical field, concretely relates to a top cover subassembly and secondary battery, wherein, the battery top cover subassembly of the application includes the pole and is used for assembling the upper plastic and lower plastic of pole, is provided with the top cover piece between the upper plastic and lower plastic, is provided with the heat conduction phase change layer between the top cover piece and lower plastic, the top cover piece and pole are insulated by the upper plastic and lower plastic setting, the phase change temperature of heat conduction phase change material layer is 100 DEG C to 120 DEG C. When temperature is greater than threshold temperature, heat conduction phase change layer melts, when temperature is less than threshold temperature, heat conduction phase change layer solidifies, thereby avoid the technical defect of sealing failure due to the heat melting of sealing ring and plastic part in the reuse process of pole, simultaneously, the application also makes corresponding improvement to existing secondary battery, improves the sealing performance and heat dissipation performance of secondary battery.

Description

Technical Field

[0001] This utility model belongs to the field of battery top cover technology, specifically relating to a top cover assembly and a secondary battery. Background Technology

[0002] With the rapid development of energy storage, smart grids, and electric vehicles, lithium-ion batteries are widely used due to their high energy density, long cycle life, and excellent high-rate performance. Therefore, higher standards have been set for the reliability and safety of lithium-ion batteries, with battery sealing being particularly critical. As a key component connecting the battery to external devices, leakage at the terminals can not only cause individual cell failure but may also halt the entire battery pack due to electrolyte leakage, potentially leading to other safety issues and accidents.

[0003] In a typical manufacturing process, the electrode post passes sequentially through the lower plastic layer, the sealing ring, the electrode post through-hole in the top cover plate, and the upper plastic layer. The sealing ring's function is to seal any gaps and ensure the airtightness of the positive and negative electrodes in the top cover plate structure. However, in actual production, a perfect tight fit between the sealing ring and the plastic is often not achieved. Although the initial design intent was to deform the sealing ring during installation to achieve a sealed connection with the plastic, in practical applications, when the electrode post generates significant heat, it may cause the sealing ring and plastic parts to melt, leading to seal failure.

[0004] Therefore, it is urgent to improve the existing battery top cover assembly and secondary battery to solve the technical defects of the existing technology. Utility Model Content

[0005] One of the objectives of this utility model is to provide a battery top cover assembly that avoids the technical defects of sealing failure caused by the thermal melting of the sealing ring and plastic parts, which are inadequate in the existing technology.

[0006] To solve the above-mentioned technical problems, this application implements the following technical solution:

[0007] A top cover assembly includes an electrode post and an upper plastic and a lower plastic for assembling the electrode post. A top cover sheet is disposed between the upper plastic and the lower plastic, and a thermally conductive phase change layer is disposed between the top cover sheet and the lower plastic. The top cover sheet and the electrode post are insulated from each other by the upper plastic and the lower plastic.

[0008] The phase transition temperature of the thermally conductive phase change material layer is 100℃-120℃.

[0009] The above technical solution produces the following technical effects:

[0010] This technical solution aims to address the heat dissipation problem of the top cover assembly when the battery cell generates high heat. By designing a thermally conductive phase change layer, when the temperature exceeds a set threshold, the phase change material in the layer melts and becomes soft. Under the pressure of the top cover sheet, the molten thermally conductive phase change layer fills the gaps in the underlying plastic. When the temperature drops back to room temperature (below the threshold temperature), the thermally conductive phase change layer re-solidifies, not only resealing the battery cell but also filling the gaps in the underlying plastic, effectively avoiding sealing problems caused by defects in the plastic itself.

[0011] As a further improvement to the top cover assembly of this utility model, the thermally conductive phase change layer is organic polyethylene glycol.

[0012] As a further improvement to the top cover assembly of this utility model, the top cover plate and the pole are sealed together by a thermally conductive phase change layer.

[0013] As a further improvement to the top cover assembly of this utility model, the thermally conductive phase change layer disposed between the top cover sheet and the pole post is connected to the upper plastic along the thickness and height direction of the pole post.

[0014] As a further improvement to the top cover assembly of this utility model, the lower plastic extends along its length and is provided with an extension portion, which is between the extension portion and the connecting piece disposed on the thermally conductive phase change layer and the bottom of the pole post.

[0015] As a further improvement to the top cover assembly of this utility model, the top cover sheet is provided with a first end and a first connecting part along both sides of the pole post, and the lower plastic is provided with a second end and a second connecting part along both sides of the pole post.

[0016] A thermally conductive phase change layer is provided between the first connecting parts and the second connecting parts, and a thermally conductive phase change layer is also provided between the first end and the second end.

[0017] The heat generated by the thermally conductive phase change interlayer electrode between the first and second ends is conducted out of the top cover assembly.

[0018] As a further improvement to the top cover assembly of this utility model, the upper plastic is provided with an embedding groove, which is used to embed the first protrusion of the top cover piece.

[0019] As a further improvement to the top cover assembly of this utility model, the pole post is provided with a recess, which is used to receive the second protrusion of the upper plastic.

[0020] As a further improvement to the top cover assembly of this utility model, the thermally conductive phase change layer has an irregular shape.

[0021] The second objective of this utility model is to provide a secondary battery that avoids the technical defects of sealing failure caused by the thermal melting of the sealing ring and plastic parts, which are inadequate in the existing technology.

[0022] To solve the above-mentioned technical problems, this application implements the following technical solution:

[0023] A secondary battery includes any of the above-mentioned top cover assembly, housing, and electrode assembly.

[0024] The above technical solution produces the following technical effects:

[0025] By employing the above technical solution, when high temperatures are generated inside the battery, the thermally conductive phase change layer can respond rapidly, melting and filling the tiny gaps between the plastic components, thereby effectively preventing electrolyte leakage and ensuring the safety and reliability of the battery. Simultaneously, when the temperature drops below a threshold, the thermally conductive phase change layer re-solidifies, maintaining a stable sealing effect and providing long-lasting protection for the battery.

[0026] Furthermore, the top cover assembly and secondary battery in this invention, through optimized structural design, enable the thermally conductive phase change layer to distribute heat more evenly, improve heat dissipation efficiency, and further extend the battery's service life. Attached Figure Description

[0027] The accompanying drawings, which are included to provide a further understanding of the present invention and constitute a part of this invention, illustrate exemplary embodiments of the present invention and are used to explain the present invention, but do not constitute an undue limitation of the present invention. In the drawings:

[0028] Figure 1 This is a schematic diagram of the top cover assembly in Embodiment 1 of this utility model;

[0029] Figure 2 for Figure 1 The top cover assembly shown is along the section line AA;

[0030] Figure 3 for Figure 2 A magnified view of a portion at point A;

[0031] in:

[0032] 1-Pole post;

[0033] 2- Apply plastic;

[0034] 21-The second convex part;

[0035] 3-Lower plastic;

[0036] 31-Extension;

[0037] 32 - Second end;

[0038] 33-Second connecting part;

[0039] 4-Top cover plate;

[0040] 41 - First end;

[0041] 42-First connecting part;

[0042] 43-First convex part;

[0043] 5- Thermally conductive phase change layer. Detailed Implementation

[0044] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terminology used in the specification of this application is only for describing specific embodiments and is not intended to limit this application.

[0045] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing" 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. Although this application discloses preferred embodiments as described above, it is not intended to limit the claims. Any person skilled in the art can make several possible variations and modifications without departing from the concept of this application. Therefore, the scope of protection of this application should be determined by the scope defined in the claims of this application.

[0046] The present invention will be further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0047] Implementation Method 1

[0048] CN220797000U discloses a method for improving sealing. The sealing ring of this invention has a convex lower flange on its outer periphery, and the lower plastic body 3 has a corresponding convex upper flange, thus enhancing sealing performance. However, this method cannot effectively solve the sealing failure caused by high heat generation.

[0049] like Figure 1-2As shown, this application improves upon existing battery top cover assemblies to address the technical defect of thermal failure of sealing components (flanges in the aforementioned patent, but sealing rings are more common in the prior art) caused by heat generated during charging and discharging of the terminal post 1. Specifically,

[0050] The top cover assembly of this application includes an electrode post 1 and upper plastic 2 and lower plastic 3 for assembling the electrode post. A top cover sheet 4 is disposed between the upper plastic 2 and lower plastic 3, and a thermally conductive phase change layer 5 is disposed between the top cover sheet 4 and lower plastic 3. The top cover sheet 4 and the electrode post 1 are insulated from each other by the upper plastic 2 and lower plastic 4. The phase change temperature of the thermally conductive phase change layer 5 is 100℃-120℃. When the temperature is higher than the threshold temperature (any temperature value in the range of 100℃-120℃), the thermally conductive phase change layer 5 melts; when the temperature is lower than the threshold temperature (any temperature value in the range of 100℃-120℃), the thermally conductive phase change layer 5 solidifies.

[0051] Therefore, this application effectively solves the sealing failure problem caused by heat generation in the electrode post 1 by incorporating a thermally conductive phase change layer 5. When the electrode post 1 generates high heat, the thermally conductive phase change layer 5 melts and fills the gaps between the plastic parts, preventing electrolyte leakage. When the temperature drops below the threshold, the thermally conductive phase change layer 5 re-solidifies, maintaining a stable sealing state. In addition, the thermally conductive phase change layer 5 can optimize heat distribution, improve heat dissipation efficiency, and further extend the battery's lifespan.

[0052] In practical implementation, the threshold temperature of the thermally conductive phase change layer 5 can be flexibly set according to the heat dissipation requirements and safety performance requirements of different types of batteries. For example, for high-energy-density lithium-ion batteries that are prone to high temperatures, a lower threshold temperature can be selected to ensure that the thermally conductive phase change layer 5 can respond quickly, melt and fill gaps when the battery temperature rises slightly, preventing electrolyte leakage and ensuring battery safety. Conversely, for batteries with good heat dissipation performance and small temperature fluctuations, a higher threshold temperature can be selected to avoid the thermally conductive phase change layer 5 from frequently melting and solidifying unnecessarily, which would affect the battery's sealing performance and lifespan.

[0053] Furthermore, the thermally conductive phase change layer 5 is made of organic polyethylene glycol. Organic polyethylene glycol has good thermal stability and chemical inertness, and can maintain stable physical and chemical properties over a wide temperature range, thereby ensuring the reliability and durability of the thermally conductive phase change layer 5 during battery operation.

[0054] Furthermore, the top cover plate 4 and the terminal post 1 are sealed together by a thermally conductive phase change layer 5. Thus, the integrated thermally conductive phase change layer 5 between the top cover plate 4 and the terminal post 1, and between the top cover plate 4 and the lower plastic 3, not only achieves effective heat conduction and prevents the risk of current short circuit, but also further improves the safety performance of the battery.

[0055] Implementation Method 2

[0056] like Figure 1-3 As shown, in order to further improve the sealing effect of the top cover assembly, a thermally conductive phase change layer 5 is further disposed between the top cover plate 4 and the electrode post 1 along the thickness height direction of the electrode post 1 (e.g., Figure 2 (As shown in the Y-axis direction) it is connected to the upper plastic 2. The thermally conductive phase change layer 5 forms a tighter wrap around the electrode post 1, enhancing its bonding force with the upper plastic 2 and further improving sealing performance. When the electrode post 1 generates heat, the thermally conductive phase change layer 5 can respond more quickly, melting and filling any possible tiny gaps, effectively preventing electrolyte leakage. Simultaneously, this design optimizes the heat conduction path, allowing heat to be distributed more evenly throughout the top cover assembly, improving heat dissipation efficiency.

[0057] Furthermore, the top cover plate 4 is provided with a first end 41 and a first connecting part 42 along both sides of the pole post 1, and the lower plastic 3 is provided with a second end 32 and a second connecting part 33 along both sides of the pole post 1; a thermally conductive phase change layer 5 is provided between the first connecting part 42 and the first connecting part 42, and a thermally conductive phase change layer 5 is also provided between the first end 41 and the second end 32; the heat generated by the pole post 1 between the thermally conductive phase change layer 5 between the first end 41 and the second end 32 is conducted out of the top cover assembly.

[0058] Therefore, the thermally conductive phase change layer 5 not only effectively conducts the heat generated by the electrode post 1 to the outside of the top cover assembly, but also enhances the structural connection between the top cover sheet 4 and the lower plastic 3, improving overall stability and sealing. In practical applications, this design can significantly reduce sealing failure caused by temperature fluctuations, ensuring the reliability and safety of the battery under various operating conditions.

[0059] Furthermore, the embedding groove on the upper plastic 2 fits tightly with the first protrusion 43 of the top cover plate 4. This structural design not only simplifies the assembly process but also improves the overall strength of the top cover assembly. At the same time, the recess on the pole post 1 fits with the second protrusion 21 of the upper plastic 2, further enhancing the connection stability between the pole post 1 and the upper plastic 2 and avoiding connection loosening problems caused by vibration or impact.

[0060] Preferably, the thermally conductive phase change layer 5 adopts an irregular shape design. This innovative structure can better adapt to the complex space inside the top cover assembly, ensuring uniform heat distribution and effective conduction. At the same time, the irregularly shaped thermally conductive phase change layer 5 can more fully fill the tiny gaps between plastic parts after melting, further improving the sealing performance.

[0061] Therefore, the secondary battery assembled with the top cover assembly of this utility model effectively solves the sealing failure problem caused by heat generation at the terminal post 1 in the prior art. At the same time, through optimized structural design, the overall stability and heat dissipation efficiency are improved, providing a strong guarantee for the safety and reliability of the battery.

[0062] Other aspects that are the same as in Implementation Method 1 will not be described again in this implementation method.

[0063] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A top cover assembly, comprising a pole (1) and an upper plastic (2) and a lower plastic (3) for assembling the pole (1), wherein a top cover sheet (4) is disposed between the upper plastic (2) and the lower plastic (3), characterized in that, A thermally conductive phase change layer (5) is provided between the top cover plate (4) and the lower plastic (3), and the top cover plate (4) and the pole (1) are insulated from each other by the upper plastic (2) and the lower plastic (3); The phase transition temperature of the thermally conductive phase change layer (5) is 100℃-120℃.

2. A top cover assembly according to claim 1, characterized in that, The thermally conductive phase change layer (5) is organic polyethylene glycol.

3. A top cover assembly according to claim 1, characterized in that, The top cover plate (4) and the pole post (1) are sealed together by the thermally conductive phase change layer (5).

4. A top cover assembly according to claim 3, characterized in that, The thermally conductive phase change layer (5) disposed between the top cover plate (4) and the pole post (1) is connected to the upper plastic (2) along the thickness and height direction of the pole post (1).

5. A top cover assembly according to claim 1, characterized in that, The lower plastic (3) is provided with an extension (31) extending along its length direction. The extension (31) is fixedly connected to the connecting piece (11) provided at the bottom of the thermally conductive phase change layer (5) and the pole (1).

6. A top cover assembly according to claim 1, characterized in that, The top cover (4) is provided with a first end (41) and a first connecting part (42) on both sides of the pole post (1), and the lower plastic (3) is provided with a second end (32) and a second connecting part (33) on both sides of the pole post (1). The thermally conductive phase change layer (5) is provided between the first connecting part (42) and the first connecting part (42), and the thermally conductive phase change layer (5) is also provided between the first end (41) and the second end (32). The heat generated by the pole (1) between the first end (41) and the second end (32) in the thermally conductive phase change layer (5) is conducted out of the top cover assembly.

7. A top cover assembly according to claim 1, characterized in that, The upper plastic (2) is provided with an embedding groove for embedding the first protrusion (43) of the top cover (4).

8. A top cover assembly according to claim 1, characterized in that, The pole post (1) is provided with a recess, which is used to receive the second protrusion (21) of the upper plastic (2).

9. A top cover assembly according to claim 1, characterized in that, The thermally conductive phase change layer (5) has an irregular shape.

10. A secondary battery, characterized in that, Includes the top cover assembly, housing, and electrode assembly as described in any one of claims 1-9.

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