Top cover structure and battery

Abstract

The top cover structure comprises a cover plate assembly and two external electrodes, each external electrode comprises a pole, an upper plastic part and a fixing part, the upper plastic part is arranged on one side of the cover plate assembly, and the fixing part is arranged on the side, away from the cover plate assembly, of the upper plastic part. The pole penetrates through the cover plate assembly, the upper plastic part and the fixing part, and the end part of the pole is welded and fixed with the fixing part; the external electrode further comprises a heat insulation part, and the heat insulation part is located between the upper plastic part and the fixing part and used for blocking heat conduction between the upper plastic part and the fixing part. On the basis of protecting the upper plastic part from poor deformation caused by high heat, the fusion depth and the fusion width of a welding seam can be ensured, and the overall size of the battery can be reduced.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a top cover structure and a battery. Background Technology

[0002] Lithium-ion batteries have advantages such as small size, high energy density, long lifespan, and environmental friendliness, and are therefore widely used in industries such as automobiles and electronics. Taking a square lithium-ion battery as an example, the cover structure of a lithium-ion battery typically includes a top cover, an upper plastic layer, a lower plastic layer, and terminals. The upper and lower plastic layers are located on opposite sides of the top cover. One end of the terminal passes through the top cover, the upper plastic layer, and the lower plastic layer, and is welded to a component on the upper plastic layer. In related technologies, reducing the welding power or increasing the distance between the welding position and the upper plastic layer can prevent the heat generated during welding from deforming the upper plastic layer. However, reducing the welding power will decrease the weld penetration and width, while increasing the distance between the welding position and the plastic component will increase the overall size of the battery. Utility Model Content

[0003] The embodiments of this utility model provide a top cover structure and a battery, which can improve the technical problems of reduced weld depth and width or increased overall battery size caused by the protective plastic.

[0004] In a first aspect, embodiments of the present invention provide a top cover structure, comprising:

[0005] Cover plate assembly; and,

[0006] Two external electrodes are provided. Each external electrode includes an electrode post, an upper plastic part, and a fixing part. The upper plastic part is disposed on one side of the cover plate assembly, and the fixing part is disposed on the side of the upper plastic part away from the cover plate assembly. The electrode post passes through the cover plate assembly, the upper plastic part, and the fixing part, and the end of the electrode post is welded and fixed to the fixing part.

[0007] The external electrode further includes a heat insulation component, which is located between the upper plastic part and the fixing component to block heat conduction between the upper plastic part and the fixing component.

[0008] In one embodiment, the upper plastic part has a mounting groove on the side opposite to the cover plate assembly;

[0009] The fastener is disposed within the mounting groove;

[0010] The heat insulation element is located at least between the bottom of the fixing element and the bottom wall of the mounting groove.

[0011] In one embodiment, the peripheral edge of the heat insulation member is bent to form a flange, the flange being located between the side of the fixing member and the side wall of the mounting groove.

[0012] In one embodiment, the end of the flange extends beyond the opening of the mounting groove in a direction away from the cover plate assembly.

[0013] In one embodiment, the external electrode further includes a limiting protrusion and a limiting groove for plugging and engaging, wherein one of the limiting protrusion and the limiting groove is disposed on the bottom wall of the mounting groove, and the other is disposed on the bottom of the fixing member.

[0014] The heat insulation component is provided with a concave-convex structure, which corresponds to the limiting protrusion and the limiting groove.

[0015] In one embodiment, the contact area between the upper plastic part and the fixing member is set to S1, and the coverage area of ​​the heat insulation member on the upper plastic part is set to S2, wherein S2 is greater than or equal to 1 / 2S1.

[0016] In one embodiment, the heat insulation element is disposed on the side surface of the upper plastic part facing the fixing element and is attached to the fixing element.

[0017] In one embodiment, the heat insulation member is disposed on the side surface of the fixing member facing the upper plastic member and is attached to the upper plastic member.

[0018] In one embodiment, the heat insulation element is placed on the side surface of the upper plastic part opposite to the cover plate assembly;

[0019] The fastener is placed on the side of the heat insulation component facing away from the upper plastic component;

[0020] The electrode post passes through the cover plate assembly, the upper plastic part, the heat insulation part, and the fixing part. The end of the electrode post is welded and fixed to the fixing part to clamp and fix the heat insulation part between the upper plastic part and the fixing part.

[0021] In one embodiment, the thickness of the thermal insulation element is set to be greater than or equal to 20 μm.

[0022] In one embodiment, the thermal conductivity of the insulation element is set to be less than or equal to 200 W / mK.

[0023] In one embodiment, the thermal insulation component is one of an aerogel thermal insulation component, a glass wool thermal insulation component, a rock wool thermal insulation component, and a ceramic thermal insulation component.

[0024] In one embodiment, the cover plate assembly includes:

[0025] A cover plate having opposing first and second sides in its thickness direction; and,

[0026] A lower plastic component is disposed on the first side of the cover plate;

[0027] The upper plastic part is disposed on the second side of the cover plate, and the fixing part is disposed on the side of the upper plastic part away from the cover plate;

[0028] The pole is inserted through the lower plastic part, the cover plate, the upper plastic part, and the fixing member.

[0029] In one embodiment, the external electrode further includes a sealing element, which is sleeved on the outer wall of the electrode post and sandwiched between the electrode post and the cover plate assembly.

[0030] Secondly, embodiments of the present invention provide a battery, comprising:

[0031] A housing having a receiving cavity formed inside it with an opening on one side;

[0032] The aforementioned top cover structure, wherein the top cover structure covers the opening of the receiving cavity; and,

[0033] The battery cell is disposed within the receiving cavity, and the tabs of the battery cell are electrically connected to the external electrodes of the top cover structure.

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

[0035] In an embodiment of this utility model, the top cover structure includes a cover plate assembly and two external electrodes. Each external electrode includes a terminal post, an upper plastic part, and a fixing part. The upper plastic part is disposed on one side of the cover plate assembly, and the fixing part is disposed on the side of the upper plastic part away from the cover plate assembly. One end of the terminal post passes through the cover plate assembly, the upper plastic part, and the fixing part. During assembly, the end of the terminal post is welded and fixed to the fixing part. By setting a heat insulation part between the upper plastic part and the fixing part, the heat generated during welding is prevented from being conducted to the upper plastic part, thereby protecting the upper plastic part from deformation due to high heat. Furthermore, by setting a heat insulation part to protect the upper plastic part, the welding power does not need to be reduced, thus ensuring the weld penetration and width. The distance between the fixing part and the upper plastic part does not need to be increased, thus making the internal space of the top cover structure more compact and reducing the overall size of the battery. Attached Figure Description

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

[0037] Figure 1This is a schematic diagram of the top cover structure provided in an embodiment of the present utility model;

[0038] Figure 2 This is an exploded view of the top cover structure provided in an embodiment of the present invention;

[0039] Figure 3 yes Figure 1 A sectional view along the middle AA;

[0040] Figure 4 yes Figure 3 A magnified schematic diagram of part B in the middle;

[0041] Figure 5 yes Figure 1 A schematic diagram of the external electrode structure in the diagram;

[0042] Figure 6 yes Figure 5 A schematic diagram of the external electrodes in the diagram;

[0043] Figure 7 yes Figure 6 A sectional view along CC in the middle;

[0044] Figure 8 This is a schematic diagram of the battery structure provided in an embodiment of this utility model.

[0045] The names of the components corresponding to the corresponding reference numerals in the figure are:

[0046] 1000 batteries;

[0047] 100 Top cover structure; 1 Cover plate assembly; 11 Cover plate; 111 First side; 112 Second side; 12 Lower plastic part; 13 Explosion-proof hole; 14 Explosion-proof valve; 15 Explosion-proof valve protective plate; 16 Injection hole; 2 External electrode; 2a Positive external electrode; 2b Negative external electrode; 21 Electrode post; 211 End; 22 Upper plastic part; 221 Mounting groove; 2211 Groove opening; 2212 Bottom wall; 2213 Side wall; 23 Fixing component; 231 Bottom; 232 Side; 24 Heat insulation component; 241 Flanged edge; 242 Concave-convex structure; 25 Limiting protrusion; 26 Limiting groove; 27 Sealing component; 3 Pin assembly; 31 Electrode post protective plate; 32 Pin; 321 First connecting part; 322 Second connecting part;

[0048] 200 Housing; 201 Receiving cavity;

[0049] 300 cells. Detailed Implementation

[0050] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of the present utility model and are not intended to limit the present utility model. In the present utility model, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0051] Firstly, this utility model provides a top cover structure 100. (See also...) Figure 1 and Figure 2 The top cover structure 100 is used for the battery 1000. The top cover structure 100 includes a cover plate assembly 1 and two external electrodes 2. Each external electrode 2 includes a terminal post 21, an upper plastic part 22, and a fixing member 23. The upper plastic part 22 is disposed on one side of the cover plate assembly 1, and the fixing member 23 is disposed on the side of the upper plastic part 22 away from the cover plate assembly 1. One end 211 of the terminal post 21 passes through the cover plate assembly 1, the upper plastic part 22, and the fixing member 23, and the end 211 of the terminal post 21 is welded and fixed to the fixing member 23. The external electrode 2 also includes a heat insulation member 24, which is located between the upper plastic part 22 and the fixing member 23 to block heat conduction between the upper plastic part 22 and the fixing member 23.

[0052] Power-type lithium-ion batteries offer excellent rate performance, high energy density, and high safety. The top cover structure of a lithium-ion battery typically includes a cover plate 11, an upper plastic layer, a lower plastic layer, and terminals. The upper and lower plastic layers are located on opposite sides of the cover plate 11. One end of the terminal passes through the lower plastic layer, the cover plate 11, and the upper plastic layer in sequence, and is welded to a welding component above the upper plastic layer. Because the welding process between the terminal and the welding component generates significant heat, the upper plastic layer near the welding component can deform due to heat. In related technologies, reducing the welding power or increasing the distance between the welding position and the upper plastic layer can prevent this deformation. However, reducing the welding power decreases the weld penetration and width, while increasing the distance between the welding position and the plastic component increases the overall size of the battery.

[0053] In an embodiment of this utility model, the top cover structure 100 includes a cover plate assembly 1 and two external electrodes 2. Each external electrode 2 includes an electrode post 21, an upper plastic part 22, and a fixing member 23. The upper plastic part 22 is disposed on one side of the cover plate assembly 1, and the fixing member 23 is disposed on the side of the upper plastic part 22 opposite to the cover plate assembly 1. One end 211 of the electrode post 21 passes through the cover plate assembly 1, the upper plastic part 22, and the fixing member 23. During assembly, the end 211 of the electrode post 21 is welded to the fixing member 23. By providing a heat insulation component 24 between the upper plastic part 22 and the fixing component 23, the heat generated during the welding process is prevented from being conducted to the upper plastic part 22, thereby protecting the upper plastic part 22 from deformation due to high heat. Furthermore, by providing the heat insulation component 24 to protect the upper plastic part 22, the welding power does not need to be reduced, thus ensuring the weld penetration and width. The distance between the fixing component 23 and the upper plastic part 22 does not need to be increased, thus making the internal space of the top cover structure 100 more compact and reducing the overall size of the battery 1000.

[0054] It should be noted that the two external electrodes 2 can be configured as the positive external electrode 2a and the negative external electrode 2b of the top cover structure 100; the pole post 21 in the positive external electrode 2a is configured as the positive pole post; and the pole post 21 in the negative external electrode 2b is configured as the negative pole post.

[0055] Please see Figure 3 and Figure 4 The upper plastic part 22 has a mounting groove 221 on the side opposite to the cover plate assembly 1; the fixing member 23 is disposed in the mounting groove 221; the heat insulation member 24 is located at least between the bottom 231 of the fixing member 23 and the bottom wall 2212 of the mounting groove 221. By opening the mounting groove 221 on the upper plastic part 22 and placing the fixing member 23 in the mounting groove 221, the fixing member 23 is installed and positioned, which not only facilitates the assembly of the top cover structure 100 but also improves the installation stability of the fixing member 23.

[0056] In one embodiment, the heat insulation element 24 is located between the bottom 231 of the fixing element 23 and the bottom wall 2212 of the mounting groove 221.

[0057] In another embodiment, please refer to Figures 5 to 7The peripheral edge of the heat insulation component 24 is bent to form a flange 241, which is located between the side portion 232 of the fixing component 23 and the side wall 2213 of the mounting groove 221. In other words, the heat insulation component 24 can cover the bottom wall 2212 and at least part of the side wall 2213 of the mounting groove 221, thereby separating the fixing component 23 and the upper plastic component 22. This ensures that the upper plastic component 22 is not affected by the high temperature of welding, thus preventing heat deformation of the upper plastic component 22.

[0058] Specifically, in the direction away from the cover plate assembly 1, the end 211 of the flange 241 extends beyond the opening 2211 of the mounting groove 221. That is, the heat insulation member 24 can completely cover the bottom wall 2212 and side wall 2213 of the mounting groove 221, thereby completely separating the fixing member 23 and the upper plastic part 22, ensuring that the upper plastic part 22 is not affected by the high temperature of welding, and thus avoiding poor heat deformation of the upper plastic part 22.

[0059] Please see Figure 7 The external electrode 2 also includes a limiting protrusion 25 and a limiting groove 26 for plug-in engagement. One of the limiting protrusion 25 and the limiting groove 26 is disposed on the bottom wall 2212 of the mounting groove 221, and the other is disposed on the bottom 231 of the fixing member 23. The heat insulation member 24 is provided with a concave-convex structure 242, which corresponds to the limiting protrusion 25 and the limiting groove 26.

[0060] In this embodiment, the fastener 23 is installed into the mounting groove 221. A limiting protrusion 25 and a limiting groove 26 for interlocking are provided on the bottom wall 2212 of the mounting groove 221 and the bottom 231 of the fastener 23. These not only guide the fastener 23 during installation, facilitating its assembly, but also limit its position within the mounting groove 221, thus improving its installation stability. Since the heat insulation element 24 is provided between the bottom wall 2212 of the mounting groove 221 and the bottom 231 of the fastener 23, a corresponding concave-convex structure 242 is provided on the heat insulation element 24 to further increase its coverage area on the upper plastic part 22, thereby completely covering the bottom wall 2212 of the mounting groove 221.

[0061] This application does not impose specific restrictions on the placement of the limiting protrusion 25 and the limiting groove 26. In one embodiment, the limiting protrusion 25 is disposed on the bottom wall 2212 of the mounting groove 221, and the limiting groove 26 is disposed on the bottom 231 of the fixing member 23; in another embodiment, the limiting protrusion 25 is disposed on the bottom 231 of the fixing member 23, and the limiting groove 26 is disposed on the bottom wall 2212 of the mounting groove 221.

[0062] This application does not impose specific limitations on the coverage area of ​​the heat insulation component 24. The contact area between the upper plastic component 22 and the fixing component 23 is set to S1, and the coverage area of ​​the heat insulation component 24 on the upper plastic component 22 is set to S2, where S2 is greater than or equal to 1 / 2S1. That is, between the upper plastic component 22 and the fixing component 23, the coverage rate of the heat insulation component 24 on the upper plastic component 22 is greater than or equal to 50%. This ensures that the heat insulation component 24 covers a sufficient amount of the upper plastic component 22, thereby reducing the impact of welding heat on the upper plastic component 22.

[0063] This application does not impose specific restrictions on the arrangement of the heat insulation element 24.

[0064] In one embodiment, the heat insulation member 24 is disposed on the side surface of the upper plastic member 22 facing the fixing member 23 and is attached to the fixing member 23.

[0065] In one embodiment, the heat insulation member 24 is disposed on the side surface of the fixing member 23 facing the upper plastic member 22 and is attached to the upper plastic member 22.

[0066] In one embodiment, the heat insulation member 24 is placed on the side surface of the upper plastic member 22 opposite to the cover plate assembly 1; the fixing member 23 is placed on the side surface of the heat insulation member 24 opposite to the upper plastic member 22; the pole post 21 passes through the cover plate assembly 1, the upper plastic member 22, the heat insulation member 24 and the fixing member 23, and the end 211 of the pole post 21 is welded and fixed to the fixing member 23 to clamp and fix the heat insulation member 24 between the upper plastic member 22 and the fixing member 23.

[0067] In other words, the heat insulation component 24 can be disposed on the upper plastic component 22 and integrated with the upper plastic component 22; the heat insulation component 24 can be disposed on the fixing component 23 and integrated with the fixing component 23; the heat insulation component 24 can also be a separate part and assembled together with the upper plastic component 22 and the fixing component 23.

[0068] In one embodiment, the thickness of the heat insulation element 24 is set to be greater than or equal to 20 μm; setting the thickness of the heat insulation element 24 to be greater than or equal to 20 μm enables effective heat insulation by the heat insulation element 24. This application does not impose a specific limitation on the thickness of the heat insulation element 24; the thickness of the heat insulation element 24 can be set to 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, etc.

[0069] Since the heat insulation component 24 needs to block heat conduction between the upper plastic component 22 and the fixing component 23, the thermal conductivity of the heat insulation component 24 needs to be set to be less than or equal to 200 W / mK. This application does not specifically limit the material of the heat insulation component 24; the heat insulation component 24 can be one of aerogel heat insulation component 24, glass wool heat insulation component 24, rock wool heat insulation component 24, and ceramic heat insulation component 24.

[0070] Please see Figures 3 to 4 The cover plate assembly 1 includes a cover plate 11 and a lower plastic component 12; the cover plate 11 has a first side 111 and a second side 112 opposite to each other in its thickness direction F1; the lower plastic component 12 is disposed on the first side 111 of the cover plate 11; wherein, the upper plastic component 22 is disposed on the second side 112 of the cover plate 11, and the fixing member 23 is disposed on the side of the upper plastic component 22 opposite to the cover plate 11; the pole post 21 passes through the lower plastic component 12, the cover plate 11, the upper plastic component 22 and the fixing member 23.

[0071] In one embodiment, the upper plastic part 22 corresponding to the negative external electrode 2b is configured as an insulating part, preferably made of insulating PPS material, which keeps the corresponding fixing part 23 insulated from the cover plate 11. The upper plastic part 22 corresponding to the positive external electrode 2a is configured as a conductive part, preferably made of conductive PPS material, which keeps the corresponding fixing part 23 electrically connected to the cover plate 11, thereby achieving electrical connection between the positive external electrode 2a, the cover plate 11, and the aluminum casing of the battery 1000, maintaining a high potential state and preventing corrosion of the aluminum casing of the battery 1000.

[0072] It is understood that through holes are provided on the lower plastic part 12, the cover plate 11, the upper plastic part 22, and the fixing member 23. The pole post 21 passes through the through holes in sequence through the lower plastic part 12, the cover plate 11, the upper plastic part 22, and the fixing member 23. The fixing member 23 is welded and fixed to the end 211 of the pole post 21, thereby realizing the assembly of the top cover structure 100.

[0073] To ensure the sealing performance of the cover plate assembly 1, in one embodiment, the external electrode 2 further includes a sealing element 27, which is sleeved on the outer wall of the pole post 21 and sandwiched between the pole post 21 and the cover plate assembly 1. By providing the sealing element 27, the pole post 21 and the cover plate assembly 1 are interference-fitted, thereby improving the sealing performance of the cover plate 11.

[0074] In one embodiment, please refer to Figure 2 The cover plate 11 and the lower plastic part 12 are respectively provided with explosion-proof holes 13. The top cover structure 100 also includes an explosion-proof valve 14 and an explosion-proof valve protection plate 15. The explosion-proof valve 14 is located between the cover plate 11 and the lower plastic part 12 and covers the explosion-proof hole 13. The explosion-proof valve protection plate 15 is located on the side of the cover plate 11 away from the lower plastic part 12 and covers the explosion-proof hole 13. By setting the explosion-proof valve 14 and the explosion-proof valve protection plate 15, the pressure accumulated inside the battery 1000 during charging and discharging is balanced, and the battery 1000 is prevented from exploding.

[0075] In one embodiment, the cover plate assembly 1 is further provided with an injection hole 16 for injecting electrolyte into the battery 1000.

[0076] And, please see Figure 2 The top cover structure 100 further includes two pin assemblies 3, each corresponding to one of the two external electrodes 2. Each pin assembly 3 includes a pole post protection piece 31 and a pin 32. The pin 32 is bent and forms a first connecting portion 321 and a second connecting portion 322. The pin 32 is located on the side of the lower plastic part 12 facing away from the cover plate 11. The first connecting portion 321 is electrically connected to the pole post 21, and the second connecting portion 322 is arranged in a direction facing away from the lower plastic part 12, and is used for electrical connection with the core electrode tab.

[0077] Secondly, embodiments of this application also provide a battery 1000. Please refer to... Figure 8 The battery 1000 includes a housing 200, a top cover structure 100, and a battery cell 300; the housing 200 has a receiving cavity 201 with an opening on one side; the top cover structure 100 covers the opening of the receiving cavity 201; the battery cell 300 is disposed in the receiving cavity 201, and the tabs of the battery cell 300 are electrically connected to the external electrode 2 of the top cover structure 100.

[0078] It should be noted that the top cover structure 100 is configured as described above, that is, the top cover structure 100 has all the technical features of the top cover structure 100 described above, that is, the battery 1000 includes all embodiments of the top cover structure 100 described above.

[0079] The battery cell 300 is disposed within the receiving cavity 201 of the housing 200, and the top cover structure 100 covers the opening of the receiving cavity 201. The top cover structure 100 includes a cover plate assembly 1 and two external electrodes 2. Each external electrode 2 includes a terminal post 21, an upper plastic part 22, and a fixing member 23. During assembly, the end 211 of the terminal post 21 is welded and fixed to the fixing member 23. By providing a heat insulation member 24 between the upper plastic part 22 and the fixing member 23, the heat generated during welding is prevented from being conducted to the upper plastic part 22, thereby protecting the upper plastic part 22 from deformation due to high heat. Furthermore, by providing the heat insulation member 24 to protect the upper plastic part 22, the welding power does not need to be reduced, thus ensuring the weld penetration and width. The distance between the fixing member 23 and the upper plastic part 22 does not need to be increased, thus making the internal space of the top cover structure 100 more compact and reducing the overall size of the battery 1000.

[0080] This application does not impose specific limitations on the battery 1000. The battery 1000 may be configured as a lithium battery 1000, and preferably, the battery 1000 is configured as a square lithium-ion battery 1000.

[0081] The embodiments of this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this utility model. 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 utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A top cover structure for a battery, characterized in that, include: Cover plate assembly; as well as, Two external electrodes are provided. Each external electrode includes an electrode post, an upper plastic part, and a fixing part. The upper plastic part is disposed on one side of the cover plate assembly, and the fixing part is disposed on the side of the upper plastic part away from the cover plate assembly. The electrode post passes through the cover plate assembly, the upper plastic part, and the fixing part, and the end of the electrode post is welded and fixed to the fixing part. The external electrode further includes a heat insulation component, which is located between the upper plastic part and the fixing component to block heat conduction between the upper plastic part and the fixing component.

2. The top cover structure according to claim 1, characterized in that, The upper plastic part has a mounting groove on the side opposite to the cover plate assembly; The fastener is disposed within the mounting groove; The heat insulation element is located at least between the bottom of the fixing element and the bottom wall of the mounting groove.

3. The top cover structure according to claim 2, characterized in that, The peripheral edge of the heat insulation component is bent to form a flange, which is located between the side of the fixing component and the side wall of the mounting groove.

4. The top cover structure according to claim 3, characterized in that, In the direction away from the cover plate assembly, the end of the flange extends beyond the opening of the mounting groove.

5. The top cover structure according to claim 2, characterized in that, The external electrode also includes a limiting protrusion and a limiting groove for plugging and mating. One of the limiting protrusion and the limiting groove is disposed on the bottom wall of the mounting groove, and the other is disposed on the bottom of the fixing member. The heat insulation component is provided with a concave-convex structure, which corresponds to the limiting protrusion and the limiting groove.

6. The top cover structure according to claim 1, characterized in that, The contact area between the upper plastic part and the fixing part is set to S1, and the coverage area of ​​the heat insulation part on the upper plastic part is set to S2, where S2 is greater than or equal to 1 / 2S1.

7. The top cover structure according to claim 1, characterized in that, The heat insulation component is disposed on the side surface of the upper plastic component facing the fixing component and is attached to the fixing component.

8. The top cover structure according to claim 1, characterized in that, The heat insulation component is disposed on the side surface of the fixing component facing the upper plastic component and is attached to the upper plastic component.

9. The top cover structure according to claim 1, characterized in that, The heat insulation component is placed on the side surface of the upper plastic component opposite to the cover plate assembly; The fastener is placed on the side of the heat insulation component facing away from the upper plastic component; The electrode post passes through the cover plate assembly, the upper plastic part, the heat insulation part, and the fixing part. The end of the electrode post is welded and fixed to the fixing part to clamp and fix the heat insulation part between the upper plastic part and the fixing part.

10. The top cover structure according to any one of claims 2-9, characterized in that, The thickness of the heat insulation component is set to be greater than or equal to 20 μm.

11. The top cover structure according to any one of claims 2-9, characterized in that, The thermal conductivity of the insulation component is set to be less than or equal to 200 W / mK.

12. The top cover structure according to claim 11, characterized in that, The thermal insulation component is configured as one of the following: aerogel thermal insulation component, glass wool thermal insulation component, rock wool thermal insulation component, and ceramic thermal insulation component.

13. The top cover structure according to claim 1, characterized in that, The cover plate assembly includes: A cover plate having opposing first and second sides in its thickness direction; and, A lower plastic component is disposed on the first side of the cover plate; The upper plastic part is disposed on the second side of the cover plate, and the fixing part is disposed on the side of the upper plastic part away from the cover plate; The pole is inserted through the lower plastic part, the cover plate, the upper plastic part, and the fixing member.

14. The top cover structure according to claim 1, characterized in that, The external electrode also includes a sealing element, which is sleeved on the outer wall of the electrode post and sandwiched between the electrode post and the cover plate assembly.

15. A battery, characterized in that, include: A housing having a receiving cavity formed inside it with an opening on one side; The top cover structure as described in any one of claims 1-14, wherein the top cover structure covers the opening of the receiving cavity; and, The battery cell is disposed within the receiving cavity, and the tabs of the battery cell are electrically connected to the external electrodes of the top cover structure.

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