Cylindrical battery cover plate assembly and cylindrical battery

Abstract

The utility model discloses a cylindrical battery cover plate assembly and a cylindrical battery. The cylindrical battery cover plate assembly comprises a positive electrode cover plate assembly and a positive electrode confluence plate assembly, a negative electrode cover plate assembly and a negative electrode confluence disc assembly; the positive electrode cover plate assembly comprises a positive electrode end plate, a through hole is formed in the positive electrode end plate, an anti-explosion valve aluminum sheet is installed in the through hole, the upper end face of the positive electrode end plate is covered with a protective film, and a welding part used for welding an external connecting sheet is further arranged in the middle of the positive electrode end plate. The liquid injection efficiency is improved due to the design of the liquid injection hole in the center of the positive pole; the first main body of the confluence plate is light and thin, so that easy welding with a roll core tab is ensured; and the welding structure of the second main body of the convergence disc and the pole ensures the visualization of the welding process, so that the manufacturing efficiency and the production yield of the battery cover plate are improved, and the manufacturing cost is reduced. By adopting the injection molding structure and knurling the top of the negative pole, the contact area between the components is increased, the mechanical strength of the cover plate is improved, the heat dissipation capability of the battery cell is enhanced, and the performance such as the rate and cycle of the battery cell is facilitated.

Description

Technical Field

[0001] The utility model belongs to the technical field of battery covers, and in particular relates to a cylindrical battery cover assembly and a cylindrical battery. Background Art

[0002] Cylindrical batteries generally consist of a coil core, a casing, and top and bottom components. The top and bottom structures, which serve as internal current guides and external electrical connections, are called cover plates, and can be divided into positive and negative cover plates. The cover plates are typically connected using either flexible or rigid connections.

[0003] Soft connection solution: The busbar is ultrasonically or laser welded to the pole, and the pole is riveted to the top cover, sealing ring, upper and lower plastic, and terminal. In this solution, after the busbar is welded to the winding core tab, the tab needs to be bent once or twice, and then the cover plate is sealed around the perimeter to form the battery. Hard connection solution: After the collector plate is laser welded to the winding core, resistance welding or laser welding is used to pass the welding needle through the hole in the center of the winding core to directly connect the collector plate to the external pole.

[0004] The existing soft connection, that is, the riveted integrated solution has the following defects: 1. After the busbar is welded and bent, the internal gap is large, and the proportion in the height direction of the core is reduced, affecting the battery energy density. 2. Under vehicle-mounted or vibration conditions, repeated vibrations are prone to occur, and wear and tear will produce metal chips, which seriously cause short-circuit safety hazards. In addition, the misalignment after welding causes pulling and causes the tabs to fall off, affecting the electrical connection performance. 3. Due to the existence of gaps in the axial direction, the heat generated by the battery cells in the core cannot be well transferred to the upper and lower shells, affecting heat dissipation, thereby affecting the battery cell power and cycle performance.

[0005] Existing hard-connect solutions have the following drawbacks: 1. Since the collector plate is welded to the terminal through the perforated core, this invisible welding method is prone to poor welding, affecting yield. Furthermore, internal welding produces residual slag inside the cell, which can easily cause short circuits and pose safety risks. 2. The collector plate is in direct contact with the lower plastic, which also prevents good heat dissipation and affects cell performance.

[0006] Therefore, in order to solve the problems of metal chips caused by vibration wear of the soft connection of the cover, poor heat dissipation of the battery cells, invisible welding of the hard connection of the cover, residual welding slag leading to battery short circuit and low yield, it is urgent to design a new type of cylindrical battery cover to solve the above problems. Utility Model Content

[0007] The purpose of this utility model is to provide a cylindrical battery cover assembly and a cylindrical battery to solve the problems raised in the above background technology. The following technical solution is provided: A cylindrical battery cover assembly, comprising:

[0008] A positive electrode cover plate assembly, the lower end of which is welded with a positive electrode busbar assembly, and the positive electrode cover plate assembly and the positive electrode busbar assembly are respectively fixed to the positive end of the cylindrical battery;

[0009] The negative electrode cover plate assembly has a negative electrode busbar assembly welded to its lower end, and the other end of the negative electrode cover plate assembly is fixedly connected to the negative end of the cylindrical battery.

[0010] The positive electrode cover plate assembly includes a positive terminal plate, which is provided with a through hole, in which an explosion-proof valve aluminum sheet is installed, and the upper end surface of the explosion-proof valve aluminum sheet is covered with a protective film. A welding part for welding an external connecting sheet is also provided in the middle of the positive terminal plate.

[0011] In this technical solution, the welding portion is located on the plane of the upper end surface of the positive terminal plate. The welding portion is in a raised ring shape and is used for welding external connecting pieces to isolate and protect the battery cell body.

[0012] In any of the above technical solutions, further, the positive busbar assembly includes a positive busbar first body, on which first infiltration holes are symmetrically distributed, a positive busbar second body is welded to the upper end of the positive busbar first body, and a positive pole column is welded to the upper end of the positive busbar second body; and an injection hole is opened in the middle of the positive pole column.

[0013] In this technical solution, a liquid injection hole is opened in the middle of the positive electrode column. The central design of the liquid injection hole and the positive electrode column is conducive to the positioning operation during production and injection, thereby improving production efficiency.

[0014] The first main body of the positive busbar adopts a thin and light design, ensuring easy welding with the winding core tab. The symmetrically distributed first infiltration holes increase the electrolyte infiltration channel, thereby reducing the injection and infiltration time. The middle of the second main body of the positive busbar presents a hollow symmetrical fan-shaped structure, and the material is the same as that of the shell and the positive cover plate assembly. After assembly with the positive cover plate assembly, the upper surface of the second main body of the positive busbar is in close contact with the lower surface of the positive cover plate assembly, which plays a role in limiting shock and providing good heat dissipation. The addition of the second main body of the negative busbar to the first main body of the negative busbar effectively increases the flow area and improves the flow capacity.

[0015] In any of the above technical solutions, further, the negative electrode cover assembly includes a lower plastic member, the upper end of which is welded to a negative terminal plate, and a fixed opening is formed in the middle of the lower plastic member and the negative terminal plate. A negative electrode post is embedded in one end of the opening, and a sealing ring is provided around the central end wall of the negative electrode post. One end of the negative electrode post is inserted through the opening in the lower plastic member and is in close contact with the lower end surface of the lower plastic member, while the other end of the negative electrode post is extended through the upper end of the negative terminal plate. An injection-molded insulating member is also provided around the upper end of the negative electrode post.

[0016] In this technical solution, the injection-molded insulation features a right-angle design, which increases the injection volume and yield rate of the injection molding and demolding process. The top of the negative electrode post features a knurled design to increase the injection molding contact surface and enhance the injection molding strength.

[0017] In any of the above technical solutions, further, the negative busbar assembly includes a first negative busbar body, on which second infiltration holes are symmetrically distributed, and a second negative busbar body is welded to the upper end of the first negative busbar body. The second negative busbar body is a cross structure with a hollow ring in the middle, and the other end of the second negative busbar body is welded to the negative pole post.

[0018] A protrusion structure for assembling with the lower plastic is fixedly provided on the edge of the second main body of the negative busbar.

[0019] In this technical solution, the negative busbar's second body is a cross-shaped structure, with a central hollow ring integrally formed with the cross structure. It is connected to the negative electrode post by welding, and the welding process is fully visible. Protrusions are symmetrically distributed around the edge of the negative busbar's second body. These protrusions can be circular, elliptical, or other irregular shapes.

[0020] After the negative busbar assembly and the negative cover plate are assembled, the raised structure makes close contact with the lower plastic, providing position limiting, shock absorption, and heat dissipation. The thickness of the negative busbar's primary body is also thin and lightweight to ensure weldability. The symmetrically distributed secondary wetting holes within the primary body also reduce injection and wetting time. Similar to the positive electrode structure, the addition of a raised structure to the primary body of the negative busbar effectively increases the flow area and improves flow capacity.

[0021] A cylindrical battery using the above cylindrical battery cover assembly:

[0022] The positive and negative electrode cover plate assemblies of the cylindrical battery include any of the above-mentioned features, and the cylindrical battery has good manufacturing efficiency, manufacturing yield, and excellent rate performance and cycle performance.

[0023] The beneficial effects of the present invention are: the design of the injection hole centered in the center of the positive electrode pole improves the injection efficiency; the lightweight and thin first body of the busbar ensures easy welding with the winding core ear; the welding structure of the second body of the busbar and the pole ensures the visualization of the welding process, thereby improving the manufacturing efficiency and production yield of the battery cover and reducing the manufacturing cost.

[0024] The negative cover assembly adopts an injection-molded structure and a knurled design on the top of the negative pole, which can increase the contact area between components and improve the mechanical strength of the cover; the second body of the busbar fits tightly with the upper cover, which plays a role in limiting and shockproofing, thereby increasing the seismic resistance and mechanical reliability of the entire cover device.

[0025] The first body of the busbar ensures weldability, and the design of the second body further improves the current-carrying capacity. The second body of the busbar is in close contact with the cover plate, which enhances the heat dissipation capacity of the battery cell and is beneficial to the battery cell rate and cycle performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the positive electrode cover assembly in the utility model;

[0027] Figure 2 It is a schematic diagram of the positive busbar assembly in the present invention;

[0028] Figure 3 It is a schematic diagram of the negative electrode cover assembly in the present utility model;

[0029] Figure 4 It is a schematic diagram of the negative busbar assembly in the present invention.

[0030] The figures in the figure are marked as: 10, positive cover assembly; 11, positive terminal plate; 12, explosion-proof valve aluminum sheet; 13, protective film; 14, welding part; 20, positive bus plate assembly; 21, positive bus plate first body; 22, positive bus plate second body; 23, positive pole; 24, first infiltration hole; 25, injection hole; 30, negative cover assembly; 31, lower plastic; 32, negative terminal plate; 33, negative pole; 34, sealing ring; 35, injection-molded insulating part; 40, negative bus plate assembly; 41, negative bus plate first body; 42, negative bus plate second body; 43, second infiltration hole; 44, protruding structure. DETAILED DESCRIPTION

[0031] The following will be combined with the accompanying drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of this application.

[0032] In the description of this application, it should be noted that the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the exemplary embodiments according to this application. For ease of description, the dimensions of the various parts shown in the drawings are not drawn according to the actual proportional relationship. Technologies, methods and equipment known to ordinary technicians in the relevant fields may not be discussed in detail, but where appropriate, the technologies, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, so once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0033] Example 1:

[0034] like Figure 1-4 As shown, this embodiment provides a cylindrical battery cover assembly, including:

[0035] The positive electrode cover plate assembly 10 has a positive electrode busbar assembly 20 welded to its lower end. The positive electrode cover plate assembly 10 and the positive electrode busbar assembly 20 are respectively fixed to the positive end of the cylindrical battery;

[0036] The negative electrode cover plate assembly 30 has a negative electrode busbar assembly 40 welded to its lower end, and the other end of the negative electrode cover plate assembly 30 is fixedly connected to the negative end of the cylindrical battery.

[0037] The positive electrode cover plate assembly 10 includes a positive terminal plate 11, which is provided with a through hole, in which an explosion-proof valve aluminum sheet 12 is installed, and the upper end surface of the explosion-proof valve aluminum sheet 12 is covered with a protective film 13. The middle part of the positive terminal plate 11 is also provided with a welding part 14 for welding an external connecting piece.

[0038] In this technical solution, the welding portion 14 is located on the plane of the upper end surface of the positive terminal plate 11. The welding portion 14 is in a raised ring shape and is used for welding external connecting pieces to isolate and protect the battery body.

[0039] In a preferred embodiment of the present invention:

[0040] like Figure 2 As shown, specifically, the positive busbar assembly 20 includes a positive busbar first body 21, on which first infiltration holes 24 are symmetrically distributed, a positive busbar second body 22 is welded to the upper end of the positive busbar first body 21, and a positive pole column 23 is welded to the upper end of the positive busbar second body 22; a liquid injection hole 25 is opened in the middle of the positive pole column 23.

[0041] In this technical solution, a liquid injection hole 25 is opened in the middle of the positive electrode column 23. The central design of the liquid injection hole 25 and the positive electrode column 23 is conducive to the positioning operation during production and injection, thereby improving production efficiency.

[0042] The first main body 21 of the positive busbar adopts a light and thin design to ensure easy welding with the winding core tab. The symmetrically distributed first infiltration holes 24 increase the electrolyte infiltration channel, thereby reducing the injection and infiltration time. The middle of the second main body 22 of the positive busbar presents a hollow symmetrical fan-shaped structure, and the material is the same as that of the shell and the positive cover assembly 10. After assembly with the positive cover assembly 10, the upper surface of the second main body 22 of the positive busbar is in close contact with the lower surface of the positive cover assembly 10, which plays a role in limiting shock and good heat dissipation. In addition, the negative busbar second main body 42 is added on the basis of the first main body 41 of the negative busbar, which effectively increases the flow area and improves the flow capacity.

[0043] In a preferred embodiment of the present invention:

[0044] like Figure 3 As shown, the negative electrode cover plate assembly 30 specifically includes a lower plastic 31, with a negative terminal plate 32 welded to the upper end of the lower plastic 31. A hole is fixedly formed in the middle of the lower plastic 31 and the negative terminal plate 32. A negative electrode post 33 is embedded in one end of the hole. A sealing ring 34 is sleeved around the middle end wall of the negative electrode post 33. One end of the negative electrode post 33 passes through the hole in the lower plastic 31 and is tightly attached to the lower end surface of the lower plastic 31. The other end of the negative electrode post 33 passes through the upper end of the negative terminal plate 32. An injection-molded insulating member 35 is also sleeved at the upper end of the negative electrode post 33.

[0045] In this technical solution, the injection-molded insulator 35 is designed with a right angle, which can improve the injection volume and the yield rate of the injection molding process. The top of the negative electrode 33 has a knurling design to increase the injection molding contact surface and improve the injection molding strength.

[0046] In a preferred embodiment of the present invention:

[0047] like Figure 4 As shown, specifically, the negative bus plate assembly 40 includes a negative bus plate first body 41, on which second infiltration holes 43 are symmetrically distributed, and a negative bus plate second body 42 is welded to the upper end of the negative bus plate first body 41. The negative bus plate second body 42 is a cross structure with a hollow ring in the middle, and the other end of the negative bus plate second body 42 is welded to the negative pole 33.

[0048] A protrusion structure 44 for assembling with the lower plastic 31 is fixedly provided on the edge of the second body 42 of the negative busbar.

[0049] In this technical solution, the negative busbar's second body 42 is a cross-shaped structure, with a central hollow ring integrally formed with the cross structure. It is welded to the negative electrode post 33, and the welding process is fully visible. Protrusions 44 are symmetrically distributed around the edges of the negative busbar's second body 42. These protrusions 44 can be circular, elliptical, or other irregular shapes.

[0050] After the negative busbar assembly 40 and the negative cover plate assembly 30 are assembled, the raised structure 44 makes close contact with the lower plastic 31, providing position limiting, shockproofing, and heat dissipation. The first body 41 of the negative busbar is also designed to be thin and lightweight to ensure weldability. The symmetrically distributed second infiltration holes 43 within the first body 41 also reduce the injection and infiltration time. Similar to the positive electrode structure, the addition of the raised structure 44 to the first body 41 effectively increases the flow area and improves the flow capacity.

[0051] A cylindrical battery using the above cylindrical battery cover assembly:

[0052] The positive and negative electrode cover plate assemblies of the cylindrical battery include any of the above-mentioned features, and the cylindrical battery has good manufacturing efficiency, manufacturing yield, and excellent rate performance and cycle performance.

[0053] The embodiments of the present application are described above in conjunction with the accompanying drawings. Unless there is a conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms without departing from the purpose of this application and the scope of protection of the claims, all of which are within the protection of this application.

Claims

1. A cylindrical battery cover assembly, characterized in that: include: A positive electrode cover plate assembly (10), wherein a positive electrode busbar assembly (20) is welded to the lower end of the positive electrode cover plate assembly (10), and the positive electrode cover plate assembly (10) and the positive electrode busbar assembly (20) are respectively fixed to the positive end of the cylindrical battery; A negative electrode cover plate assembly (30) is welded to the lower end of the negative electrode cover plate assembly (30) with a negative electrode busbar assembly (40), and the other end of the negative electrode cover plate assembly (30) is fixedly connected to the negative end of the cylindrical battery.

2. A cylindrical battery cover assembly according to claim 1, characterized in that: The positive electrode cover plate assembly (10) comprises: A positive terminal plate (11) is provided with a through hole, an explosion-proof valve aluminum sheet (12) is installed in the through hole, and the upper end surface of the explosion-proof valve aluminum sheet (12) is covered with a protective film (13), and a welding portion (14) for welding an external connecting sheet is further provided in the middle of the positive terminal plate (11).

3. A cylindrical battery cover assembly according to claim 2, characterized in that: The positive busbar assembly (20) comprises: A positive electrode busbar first body (21) is provided, wherein first infiltration holes (24) are symmetrically distributed on the positive electrode busbar first body (21), a positive electrode busbar second body (22) is welded to the upper end of the positive electrode busbar first body (21), and a positive electrode column (23) is welded to the upper end of the positive electrode column (23); and a liquid injection hole (25) is provided in the middle of the positive electrode column (23).

4. The cylindrical battery cover assembly according to claim 1, characterized in that: The negative electrode cover plate assembly (30) comprises: A lower plastic (31), the upper end of the lower plastic (31) is welded with a negative terminal plate (32), and an opening is fixedly opened in the middle of the lower plastic (31) and the negative terminal plate (32), one end of the opening is embedded with a negative pole (33), a sealing ring (34) is sleeved on the middle ring end wall of the negative pole (33), and one end of the negative pole (33) passes through the opening of the lower plastic (31) and is tightly attached to the lower end surface of the lower plastic (31), and the other end of the negative pole (33) passes through the upper end of the negative terminal plate (32).

5. The cylindrical battery cover assembly according to claim 4, characterized in that: An injection-molded insulating part (35) is also sleeved on the upper end of the negative pole (33).

6. The cylindrical battery cover assembly according to claim 4, characterized in that: The negative electrode busbar assembly (40) comprises: A negative electrode busbar first body (41) is provided with second infiltration holes (43) symmetrically distributed on the negative electrode busbar first body (41), a negative electrode busbar second body (42) is welded to the upper end of the negative electrode busbar first body (41), the negative electrode busbar second body (42) is in a cross structure with a hollow circular ring in the middle, and the other end of the negative electrode busbar second body (42) is welded to the negative electrode column (33).

7. A cylindrical battery cover assembly according to claim 6, characterized in that: A protruding structure (44) for assembling with the lower plastic (31) is fixedly provided at the edge of the second main body (42) of the negative electrode busbar.

8. A cylindrical battery, characterized in that: The cylindrical battery cover plate assembly comprises the cylindrical battery cover plate assembly according to any one of claims 1 to 7.

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