A battery top cover structure and assembly method

Abstract

The present invention belongs to the technical field of battery production and manufacturing, and specifically relates to a battery top cover structure, comprising a top cover sheet (1) and a first electrode (2) arranged on the top cover sheet (1), a sealing sleeve (4) being sleeved between the first electrode (2) and the top cover sheet (1), the first electrode (2) comprising a conductive member (21) and a welding member (22), the top of the welding member (22) passing through the top cover sheet (1) and fixed to the conductive member (21), and the bottom of the welding member (22) being fixed to the bottom surface of the top cover sheet (1) by a lower plastic (5). The present invention eliminates the need for injection molding, reduces the risk of material deformation, and at the same time ensures the sealing performance between the top cover and the electrode, which helps to improve the safety performance of the battery cell. In addition, the present invention also discloses an assembly method for a battery top cover structure.

Description

Technical Field

[0001] The invention belongs to the technical field of battery production and manufacturing, and specifically relates to a battery top cover structure and an assembly method. Background Art

[0002] Nowadays, with the development of modern society and the enhancement of people's environmental awareness, more and more devices choose lithium batteries as power sources, such as mobile phones, laptops, power tools and electric vehicles, etc., which provides a broad space for the application and development of lithium batteries. Among them, lithium batteries used in power tools and electric vehicles are generally called power batteries. The top cover pole structure has been widely used in the top cover setting of power batteries. Usually, the top cover sheet is designed with a first pole through hole and a second pole through hole, which are fastened to the pole by injection molding and sealed on the top cover sheet to realize the electrical connection function.

[0003] The inventors found that the existing scheme still has at least the following defects: the top cover pole assembly process is complicated, and the risk of failure of the injection molded parts is high, which will produce secondary crystallization and stress, causing the injection molded parts to deform and cause pole leakage, thereby reducing the safety performance of the battery cell or even causing it to be scrapped. Summary of the invention

[0004] The purpose of the present invention is to provide a battery top cover structure to address the deficiencies of the prior art, thereby eliminating injection molded parts and reducing the risk of material deformation. At the same time, the sealing performance between the top cover and the electrode is ensured, which helps to improve the safety performance of the battery cell.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] A battery top cover structure comprises a top cover sheet and a first electrode arranged on the top cover sheet, a sealing sleeve is sleeved between the first electrode and the top cover sheet, the first electrode comprises a conductive part and a welding part, the top of the welding part passes through the top cover sheet and is fixed to the conductive part, and the bottom of the welding part is fixed to the bottom surface of the top cover sheet through a lower plastic.

[0007] As an improvement of the battery top cover structure described in the present invention, the conductive part includes a plate body and a boss installed on the bottom of the plate body, the welding part includes a ring body and a boss arranged on the ring body, and the top of the boss is provided with a welding hole that cooperates with the boss.

[0008] As an improvement of a battery top cover structure described in the present invention, the sealing sleeve includes a sleeve body and a convex portion arranged at the bottom of the sleeve body, the convex portion is provided with a through hole, and a first recessed portion for accommodating the plate body is formed at the top of the through hole, and the convex column passes through the through hole and is inserted into the convex portion.

[0009] As an improvement of the battery top cover structure described in the present invention, the edge of the ring body extends upward to form a convex edge, the bottom surface of the lower plastic is provided with a groove matching the convex edge, and the side of the convex seat corresponding to the plate body is formed with an outer edge, and the outer diameter of the outer edge is equal to the outer diameter of the plate body.

[0010] As an improvement of the battery top cover structure described in the present invention, the sealing sleeve is made of fluoroplastic injection molding or fluororubber die-cutting, the plate body and the boss are made of aluminum or copper-aluminum composite materials, and the boss and the welding part are both made of copper material.

[0011] As an improvement of the battery top cover structure described in the present invention, the top cover sheet is formed with a second electrode.

[0012] As an improvement of the battery top cover structure described in the present invention, the top cover sheet is provided with a mounting hole, the top of the mounting hole is formed with a second recess for accommodating the sealing sleeve, the bottom surface of the second recess is matched with the sealing sleeve in a concave-convex manner, and the bottom of the mounting hole is formed with a third recess for accommodating the lower plastic, the bottom surface of the third recess is matched with the lower plastic in a concave-convex manner.

[0013] As an improvement of the battery top cover structure described in the present invention, a convex body is provided on the surface of the lower plastic, and a concave body matching with the convex body is provided on the top cover sheet.

[0014] As an improvement of the battery top cover structure described in the present invention, at least one of an explosion-proof valve vent hole and a liquid injection hole is also provided on the top cover sheet, an explosion-proof valve is installed between the top cover sheet and the lower plastic, and a protective film is installed on the top of the explosion-proof valve vent hole.

[0015] A method for assembling a battery top cover structure, comprising:

[0016] Fix the lower plastic to the bottom surface of the top cover sheet, and then abut the bottom of the welding piece against the bottom surface of the lower plastic;

[0017] Pass the top of the welded part through the lower plastic, the top cover sheet and the sealing sleeve in sequence and weld them to the conductive part to ensure that the first electrode is fastened to the top cover sheet;

[0018] The negative electrode tab of the battery cell is welded to the first electrode, and then the positive electrode tab of the battery cell is welded to the second electrode.

[0019] It should be noted that, in the assembly method of the present invention, the bottom of the welding part is fixed to the bottom surface of the top cover sheet by the lower plastic, and the lower plastic plays the role of insulating the welding part and the bottom surface of the top cover sheet. The bottom of the welding part is fixed to the bottom surface of the top cover sheet, and cooperates with the first electrode to be fastened to the top cover sheet through the sealing sleeve, which is equivalent to clamping the bottom of the first electrode on the bottom surface of the top cover sheet, which helps to improve the stability between the first electrode and the top cover sheet; the first electrode is divided into a conductive part and a welding part, which is convenient for putting the sealing sleeve on the first electrode, eliminating the injection molding part for fastening the pole by injection molding process, and reducing the probability of material deformation; the sealing sleeve 4 is made of fluoroplastic injection molding or fluororubber die-cutting molding, and the assembly part has good electrical insulation performance, high heat resistance, oil resistance, solvent resistance, wear resistance, moisture resistance and low temperature resistance, which helps to extend the service life of the sealing sleeve.

[0020] The beneficial effect of the present invention is that the present invention includes a top cover sheet and a first electrode arranged on the top cover sheet, a sealing sleeve is sleeved between the first electrode and the top cover sheet, the first electrode includes a conductive part and a welding part, the top of the welding part passes through the top cover sheet and is fixed to the conductive part, and the bottom of the welding part is fixed to the bottom surface of the top cover sheet by the lower plastic. Since the existing top cover sheet is designed with first pole and second pole through-holes, the electrical connection function is realized by fastening the injection molded part to the pole and sealing sleeve on the top cover sheet, the assembly process of the top cover pole is complicated, and the risk of failure of the injection molded part is large, which will produce secondary crystallization and stress, causing the injection molded part to deform, causing the pole to leak, thereby reducing the safety performance of the battery cell, or even scrapping it. Therefore, the first electrode is divided into a conductive part and a welding part, which is convenient for putting the sealing sleeve on the first electrode, and the first electrode is fastened to the top cover sheet, which not only plays an insulating role between the top cover sheet and the first electrode, but also ensures the airtightness between the top cover sheet and the first electrode, and at the same time, eliminates the need for injection molding. The process forms an injection molded part that fastens the pole, reducing the probability of material deformation; the top of the welding part passes through the top cover sheet and is fixed to the conductive part, which can improve the stability between the welding part and the conductive part, prevent the conductive part from falling off from the sealing sleeve, and help improve the safety of the battery. At the same time, the bottom of the welding part is fixed to the bottom surface of the top cover sheet through the lower plastic, and the lower plastic plays the role of insulating the welding part and the bottom surface of the top cover sheet. The bottom of the welding part is fixed to the bottom surface of the top cover sheet, and the first electrode is fastened to the top cover sheet through the sealing sleeve, which is equivalent to clamping the bottom of the first electrode on the bottom surface of the top cover sheet, which helps to improve the stability between the first electrode and the top cover sheet. The present invention eliminates the injection molded part, reduces the risk of material deformation, and at the same time, ensures the sealing performance between the top cover and the electrode, which helps to improve the safety performance of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the present invention.

[0022] Figure 2 It is a schematic diagram of the decomposition of the present invention.

[0023] Figure 3 It is a cross-sectional schematic diagram of the first electrode after installation in the present invention.

[0024] Figure 4 It is a schematic diagram of the decomposition of the first electrode after installation in the present invention.

[0025] Figure 5 It is a cross-sectional schematic diagram of the second electrode after installation in the present invention.

[0026] Figure 6 It is a schematic structural diagram of the sealing sleeve in the present invention.

[0027] Figure 7 It is a schematic diagram of the structure of the welding part in the present invention.

[0028] Among them: 1-top cover sheet; 2-first electrode; 3-second electrode; 4-sealing sleeve; 5-lower plastic; 11-installation hole; 13-explosion-proof valve vent hole; 14-liquid injection hole; 111-second recess; 112-third recess; 21-conductive part; 22-welding part; 211-plate body; 212-convex seat; 221-ring body; 222-convex column; 2121-outer edge; 2211-convex edge; 2221-welding hole; 41-sleeve body; 42-convex part; 421-through hole; 4211-first recess; 51-groove; 52-convex body; 6-explosion-proof valve; 7-protective film. DETAILED DESCRIPTION

[0029] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. For example, "including" mentioned throughout the specification and claims is an open term, so it should be interpreted as "including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve technical problems within a certain error range and basically achieve technical effects.

[0030] In the description of the present invention, it should be understood that the directions or positional relationships indicated by the terms "upper", "lower", "front", "rear", "left", "right", "horizontal", etc. are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention.

[0031] In the invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0032] The following is combined with Figures 1 to 7 The present invention is further described in detail, but is not intended to limit the present invention.

[0033] Example 1

[0034] A battery top cover structure includes a top cover sheet 1 and a first electrode 2 arranged on the top cover sheet 1, a sealing sleeve 4 is sleeved between the first electrode 2 and the top cover sheet 1, the first electrode 2 includes a conductive member 21 and a welding member 22, the top of the welding member 22 passes through the top cover sheet 1 and is fixed to the conductive member 21, and the bottom of the welding member 22 is fixed to the bottom surface of the top cover sheet 1 through a lower plastic 5. Since the existing top cover sheet is designed with through holes for the first pole and the second pole, the electrical connection function is achieved by fastening the pole to the injection molding part and sealing the top cover sheet. The assembly process of the top cover pole is complicated, and the risk of failure of the injection molding part is high. Secondary crystallization and stress will occur, resulting in deformation of the injection molding part, causing the pole to leak, thereby reducing the safety performance of the battery cell or even scrapping it. Therefore, the first electrode 2 is divided into a conductive part 21 and a welding part 22, which is convenient for putting the sealing sleeve 4 on the first electrode 2 and fastening the first electrode 2 to the top cover sheet 1, which not only plays an insulating role between the top cover sheet 1 and the first electrode 2, but also ensures the airtightness between the top cover sheet 1 and the first electrode 2. At the same time, the injection molding part formed by the injection molding process to fasten the pole is omitted, thereby reducing the probability of material deformation. The top of the welding part 22 passes through the top cover sheet 1 and is fixed to the conductive part 21, which can improve the stability between the welding part 22 and the conductive part 21 and avoid The conductive member 21 falls off from the sealing sleeve 4, which helps to improve the safety of the battery. At the same time, the bottom of the welding member 22 is fixed to the bottom surface of the top cover sheet 1 through the lower plastic 5. The lower plastic 5 plays the role of insulating the welding member 22 and the bottom surface of the top cover sheet 1. The bottom of the welding member 22 is fixed to the bottom surface of the top cover sheet 1, and cooperates with the first electrode 2 to be fastened to the top cover sheet 1 through the sealing sleeve 4, which is equivalent to clamping the bottom of the first electrode 2 on the bottom surface of the top cover sheet 1, which helps to improve the stability between the first electrode 2 and the top cover sheet 1; the sealing sleeve 4 is made of fluoroplastic injection molding or fluororubber die-cutting molding, and the assembly part has good electrical insulation performance, high heat resistance, oil resistance, solvent resistance, wear resistance, moisture resistance and low temperature resistance, which helps to extend the service life of the sealing sleeve 4, thereby improving the safety performance of the battery cell. Compared with the injection molding parts of the encapsulation injection molding process, it is not only easy to disassemble and install, but also can reduce the cost of manufacturing batteries.

[0035] Preferably, the conductive member 21 includes a plate body 211 and a boss 212 installed at the bottom of the plate body 211 , and the welding member 22 includes a ring body 221 and a boss 222 arranged on the ring body 221 , and a welding hole 2221 matching with the boss 212 is arranged at the top of the boss 222 . The boss 212 cooperates with the welding hole 2221 to facilitate embedding the welding part 22 into the conductive part 21, which not only reduces the overall thickness of the top cover and reduces the space occupied inside the battery, thereby improving the energy density of the battery, but also facilitates welding of the conductive part 21 and the welding part 22, that is, welding is performed along the gap formed by the boss 212 and the welding hole 2221, which helps to reduce the welding cost of the conductive part 21 and the welding part 22, and simplifies the welding process, thereby helping to improve assembly efficiency; since the boss 222 is a hollow structure that protrudes upward, and the top of the boss 222 is provided with a welding hole 2221 that cooperates with the boss 212, a space for accommodating the battery cell ear is formed in the boss 222. Compared with the solid boss 222, the battery cell ear after welding can be prevented from occupying the space inside the battery, which helps to improve the space utilization inside the battery, thereby improving the energy density of the battery.

[0036] Preferably, the sealing sleeve 4 includes a sleeve body 41 and a convex portion 42 disposed at the bottom of the sleeve body 41, the convex portion 42 is provided with a through hole 421, the top of the through hole 421 is formed with a first recess 4211 for accommodating the plate body 211, and the convex column 222 passes through the through hole 421 and is inserted into the convex portion 42. The convex portion 42 is added to the bottom of the sealing sleeve 4, and the through hole 421 is provided in the convex portion 42, so that the convex column 222 can be embedded in the sealing sleeve 4, that is, the top of the welding piece 22 is surrounded, which plays an insulating role between the welding ring and the top cover sheet 1, and helps to reduce the gap between the sealing sleeve 4 and the welding piece 22, thereby improving the sealing performance between the sealing sleeve 4 and the first electrode 2; wherein, the through hole is provided on the sealing sleeve 4, so as to facilitate welding of the conductive piece 21 and the welding piece 22.

[0037] Preferably, the edge of the ring body 221 extends upward to form a convex edge 2211, and the bottom surface of the lower plastic 5 is provided with a groove 51 that matches the convex edge 2211. The convex edge 2211 and the groove 51 match each other to fix the position of the ring body 221, thereby fixing the position of the welding member 22, that is, the bottom of the welding member 22 is abutted against the bottom surface of the lower plastic 5, so that the bottom of the first electrode 2 is clamped on the bottom surface of the lower plastic 5, which helps to improve the stability between the top cover sheet 1 and the first electrode 2.

[0038] Preferably, the top cover sheet 1 is formed with a second electrode 3. The second electrode 3 is formed by integrally forming or welding the top cover sheet 1. In the present embodiment, the top cover sheet 1 protrudes upward to form a convex structure, a bump structure or other protruding structures. It is sufficient that the position of the top cover sheet 1 corresponding to the second electrode 3 protrudes upward, but the present invention is not limited thereto. The second electrode 3 can also be a planar structure, that is, it is flush with the surface of the top cover sheet 1, which helps to reduce the height of the top cover sheet 1. At the same time, the installation hole for the second electrode 3 is omitted on the top cover sheet 1, which can not only improve the sealing performance, structural stability and safety of the battery, but also reduce the manufacturing cost, and save the space occupied by the pole connector, which is conducive to reducing the volume of the battery.

[0039] Preferably, the top cover sheet 1 is provided with a mounting hole 11, and a second recess 111 for accommodating the sealing sleeve 4 is formed at the top of the mounting hole 11, and the bottom surface of the second recess 111 is matched with the sealing sleeve 4 in a concave-convex manner. The bottom of the mounting hole 11 is formed with a third recess 112 for accommodating the lower plastic 5, and the bottom surface of the third recess 112 is matched with the lower plastic 5 in a concave-convex manner. The top cover sheet 1 is provided with the second recess 111, which can partially embed the sealing sleeve 4 into the top cover sheet 1, prevent the sealing sleeve 4 from being displaced in the horizontal direction, help improve the stability between the top cover sheet 1 and the sealing sleeve 4, and also help reduce the overall thickness of the top cover structure. The top cover sheet 1 is provided with the third recess 112, which helps reduce the space occupied by the top cover structure inside the battery, which is beneficial to improving the energy density of the battery, and at the same time prevents the lower plastic 5 from being moved horizontally, and can improve the stability between the top cover sheet 1 and the lower plastic 5.

[0040] Preferably, at least one of an explosion-proof valve vent hole 13 and a liquid injection hole 14 is also provided on the top cover sheet 1, an explosion-proof valve 6 is installed between the top cover sheet 1 and the lower plastic 5, and a protective film 7 is installed on the top of the explosion-proof valve vent hole 13. The liquid injection hole 14 is convenient for injecting electrolyte into the battery, and the explosion-proof valve 6 can automatically and quickly release the pressure of the battery when the internal pressure of the battery rises due to overcharging, overdischarging, overcurrent and internal short circuit of the battery, so as to avoid the occurrence of safety accidents caused by battery explosion, and the protective film 7 can prevent external impurities from entering the explosion-proof valve 6 and affecting the function of the explosion-proof valve 6.

[0041] The working principle of the present invention is:

[0042] Since the existing top cover sheet is designed with the first pole and the second pole through-hole, the electrical connection function is realized by fastening the injection molded part to the pole and sealing the top cover sheet. The assembly process of the top cover pole is complicated, and the risk of failure of the injection molded part is high, which will produce secondary crystallization and stress, resulting in deformation of the injection molded part, causing the pole to leak, thereby reducing the safety performance of the battery cell and even scrapping it. Therefore, the first electrode 2 is divided into a conductive part 21 and a welding part 22, which is convenient for putting the sealing sleeve 4 on the first electrode 2, and the first electrode 2 is fastened to the top cover sheet 1, which not only plays the role of the top cover sheet 1 and the first electrode 2. The insulating effect between the first electrode 2 and the second electrode 2 can also ensure the airtightness between the top cover sheet 1 and the first electrode 2. At the same time, the injection molding part formed by the injection molding process to fasten the pole is omitted, and the probability of material deformation is reduced; the top of the welding part 22 passes through the top cover sheet 1 and is fixed to the conductive part 21, which can improve the stability between the welding part 22 and the conductive part 21, prevent the conductive part 21 from falling off from the sealing sleeve 4, and help improve the safety of the battery. At the same time, the bottom of the welding part 22 is fixed to the bottom surface of the top cover sheet 1 through the lower plastic 5, and the lower plastic 5 plays an insulating role. The bottom of the welding piece 22 is fixed to the bottom surface of the top cover sheet 1, and the first electrode 2 is fastened to the top cover sheet 1 through the sealing sleeve 4, which is equivalent to clamping the bottom of the first electrode 2 on the bottom surface of the top cover sheet 1, which helps to improve the stability between the first electrode 2 and the top cover sheet 1; wherein, the second electrode 3 is formed by integrally forming or welding the top cover sheet 1, and can be formed by convex upward or non-convex upward, and there is no need to reserve a mounting hole for the second electrode 3 on the top cover sheet 1, which can not only improve the battery The sealing performance, structural stability and safety of the battery are improved, and the manufacturing cost can be reduced, and the space occupied by the pole connector is saved, which is beneficial to reducing the volume of the battery; since the boss 222 is a hollow structure and protrudes upward, and the top of the boss 222 is provided with a welding hole 2221 that cooperates with the boss 212, a space for accommodating the battery cell ear is formed in the boss 222. Compared with the solid boss 222, the battery cell ear after welding can be prevented from occupying the space inside the battery, which helps to improve the space utilization inside the battery, thereby improving the energy density of the battery.

[0043] Example 2

[0044] The difference from Example 1 is that an outer edge 2121 is formed on the side of the boss 212 corresponding to the plate body 211 in this embodiment, and the outer diameter of the outer edge 2121 is equal to the outer diameter of the plate body 211. The sealing sleeve 4 is injection-molded by fluoroplastic or die-cut by fluororubber. The plate body 211 and the boss 212 are made of aluminum or copper-aluminum composite materials. The boss 212 and the welding part 22 are both made of copper material. A convex body 52 is provided on the surface of the lower plastic 5, and a concave body matching the convex body 52 is provided on the top cover sheet 1. An outer edge 2121 is provided on one side of the boss 212 corresponding to the plate body 211, which helps to increase the contact area between the boss 212 and the plate body 211, reduce the resistance of the conductive member 21, thereby reducing heat generation, and helps to improve the current carrying capacity and safety of the conductive member 21; the sealing sleeve 4 is made of fluoroplastic injection molding or fluororubber die-cutting, and has good electrical insulation performance, high heat resistance, oil resistance, solvent resistance, wear resistance, moisture resistance and low temperature resistance, which helps to extend the service life of the sealing sleeve 4; since the price of aluminum material is lower than that of copper material, when the negative electrode current collector is made of copper foil material, the boss 212 and the welding piece 22 are both materials corresponding to the negative electrode current collector, and the plate body 21 1 is made of aluminum material, and the protrusion 212 is made of copper material, which can ensure that the quality of the battery is not affected and reduce the production cost of the negative electrode; the concave-convex fit between the convex body 52 and the concave body is helpful to improve the stability between the top cover sheet 1 and the lower plastic 5. The convex body 52 can also adopt a hot melt column, and the hot melt column is melted by heating, which is equivalent to the hot melt column being completely melted into the concave body, that is, the lower plastic 5 and the top cover sheet 1 are integrated into one, reducing the riveting process, simplifying the battery manufacturing process and reducing the production cost of the battery, while reducing the overall quality of the battery without affecting the basic function of the battery, and also allowing a larger battery cell to be placed inside the battery, making the top cover structure more compact and improving the battery space utilization.

[0045] The other structures are the same as those in Example 1 and will not be described again here.

[0046] Example 3

[0047] A method for assembling a battery top cover structure, comprising:

[0048] A second electrode 3 is formed on the top cover sheet 1 by welding or integral molding;

[0049] Fix the lower plastic 5 to the bottom surface of the top cover sheet 1 so that the convex body 52 on the surface of the lower plastic 5 and the concave body on the bottom surface of the top cover sheet 1 are connected one by one, and then the bottom of the welding piece 22 is abutted against the bottom surface of the lower plastic 5 so that the convex edge 2211 of the welding piece 22 is embedded in the groove 51 on the bottom surface of the lower plastic 5;

[0050] The top of the welding piece 22 is sequentially passed through the lower plastic 5, the mounting hole 11 of the top cover sheet 1 and the through hole 421 of the sealing sleeve 4 and welded to the conductive piece 21, ensuring that the convex column 222 of the welding piece 22 is inserted into the convex portion 42, so that the first electrode 2 is fastened to the top cover sheet 1;

[0051] The negative electrode tab of the battery cell is welded to the first electrode 2 , and then the positive electrode tab of the battery cell is welded to the second electrode 3 .

[0052] It should be noted that in the assembly method of the present invention, the second electrode 3 is formed by integrally forming or welding the top cover sheet 1, and can be formed by convexly upward or not convexly upward, and there is no need to reserve a mounting hole for the second electrode 3 on the top cover sheet 1, which can not only improve the sealing performance, structural stability and safety of the battery, but also reduce the manufacturing cost, and save the space occupied by the pole connector, which is conducive to reducing the volume of the battery; the bottom of the welding piece 22 is fixed to the bottom surface of the top cover sheet 1 by the lower plastic 5, and the lower plastic 5 plays the role of insulating the welding piece 22 and the bottom surface of the top cover sheet 1, and the convex edge 2211 and the groove 51 cooperate with each other to fix the position of the ring body 221, thereby fixing the position of the welding piece 22, that is, the bottom of the welding piece 22 is abutted against the bottom surface of the lower plastic 5, so that the bottom of the first electrode 2 is clamped on the bottom surface of the lower plastic 5, which helps to improve the stability between the top cover sheet 1 and the first electrode 2; the first electrode 2 is divided into a conductive piece 21 and a welding piece 22, which is convenient for putting the sealing sleeve 4 on the first electrode 2, saving The injection molding part for fastening the pole by the injection molding process is eliminated, the probability of material deformation is reduced, the boss 222 can be embedded in the sealing sleeve 4, that is, the top of the welding piece 22 is surrounded, which plays an insulating role between the welding ring and the top cover sheet 1, which helps to reduce the gap between the sealing sleeve 4 and the welding piece 22, thereby improving the sealing performance between the sealing sleeve 4 and the first electrode 2; in addition, since the boss 222 is a hollow structure and protrudes upward, and the top of the boss 222 is provided with a welding hole 2221 that cooperates with the boss 212, a space for accommodating the battery cell ear is formed in the boss 222. Compared with the solid boss 222, the battery cell ear after welding can be prevented from occupying the space inside the battery, which helps to improve the space utilization rate inside the battery, thereby improving the energy density of the battery; the sealing sleeve 4 is made of fluoroplastic injection molding or fluororubber die-cutting molding, and the assembly part has good electrical insulation performance, high heat resistance, oil resistance, solvent resistance, wear resistance, moisture resistance and low temperature resistance, which helps to extend the service life of the sealing sleeve 4.

[0053] According to the disclosure and teaching of the above description, those skilled in the art to which the present invention belongs can also change and modify the above embodiment. Therefore, the present invention is not limited to the above specific embodiment, and any obvious improvement, replacement or modification made by those skilled in the art on the basis of the present invention belongs to the protection scope of the present invention. In addition, although some specific terms are used in this specification, these terms are only for the convenience of description and do not constitute any limitation to the present invention.

Claims

1. A battery top cover structure, characterized in that: It comprises a top cover sheet (1) and a first electrode (2) arranged on the top cover sheet (1), a sealing sleeve (4) is sleeved between the first electrode (2) and the top cover sheet (1), the first electrode (2) comprises a conductive part (21) and a welding part (22), the top of the welding part (22) passes through the top cover sheet (1) and is fixed to the conductive part (21), and the bottom of the welding part (22) is fixed to the bottom surface of the top cover sheet (1) through a lower plastic (5); The conductive member (21) comprises a plate body (211) and a convex seat (212) installed at the bottom of the plate body (211); the welding member (22) comprises a ring body (221) and a convex column (222) arranged on the ring body (221); a welding hole (2221) matching with the convex seat (212) is arranged at the top of the convex column (222); The sealing sleeve (4) comprises a sleeve body (41) and a convex portion (42) arranged at the bottom of the sleeve body (41); the convex portion (42) is provided with a through hole (421); a first concave portion (4211) for accommodating the plate body (211) is formed at the top of the through hole (421); the convex column (222) passes through the through hole (421) and is inserted into the convex portion (42); The edge of the ring body (221) extends upward to form a convex edge (2211), the bottom surface of the lower plastic (5) is provided with a groove (51) that matches the convex edge (2211), and the side of the convex seat (212) corresponding to the plate body (211) is formed with an outer edge (2121), and the outer diameter of the outer edge (2121) is equal to the outer diameter of the plate body (211); The top cover sheet (1) is provided with a mounting hole (11), the top of the mounting hole (11) is formed with a second recessed portion (111) for accommodating the sealing sleeve (4), the bottom surface of the second recessed portion (111) is matched with the sealing sleeve (4) in a concave-convex manner, and the bottom of the mounting hole (11) is formed with a third recessed portion (112) for accommodating the lower plastic (5), the bottom surface of the third recessed portion (112) is matched with the lower plastic (5) in a concave-convex manner.

2. A battery top cover structure as claimed in claim 1, characterized in that: The sealing sleeve (4) is made of fluoroplastic injection molding or fluororubber die-cutting, the plate body (211) and the boss (212) are made of aluminum or copper-aluminum composite material, and the boss (212) and the welding piece (22) are both made of copper material.

3. A battery top cover structure as claimed in claim 1, characterized in that: The top cover sheet (1) is formed with a second electrode (3).

4. A battery top cover structure as claimed in claim 1, characterized in that: The surface of the lower plastic (5) is provided with a convex body (52), and the top cover sheet (1) is provided with a concave body that matches the convex body (52).

5. A battery top cover structure as claimed in claim 1, characterized in that: The top cover sheet (1) is also provided with at least one of an explosion-proof valve vent hole (13) and a liquid injection hole (14); an explosion-proof valve (6) is installed between the top cover sheet (1) and the lower plastic (5); and a protective film (7) is installed on the top of the explosion-proof valve vent hole (13).

6. A method for assembling a battery top cover structure, characterized in that: include: Fix the lower plastic (5) to the bottom surface of the top cover sheet (1), and then abut the bottom of the welding piece (22) against the bottom surface of the lower plastic (5); The top of the welding piece (22) is sequentially passed through the lower plastic (5), the top cover sheet (1) and the sealing sleeve (4) and welded to the conductive piece (21), ensuring that the first electrode (2) is fastened to the top cover sheet (1); The negative electrode tab of the battery cell is welded to the first electrode (2), and then the positive electrode tab of the battery cell is welded to the second electrode (3).

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