A positive electrode top cover assembly of a cylindrical battery and a cylindrical battery

Abstract

This application discloses a positive electrode top cover assembly for a cylindrical battery and a cylindrical battery. The positive electrode top cover assembly includes: a top cover sheet with a boss at its center for use as a positive electrode post, and a first vent hole for pressure relief on the boss; the top cover sheet and the boss are integrally formed; a flip sheet with annular grooves on its edge; and a connecting sheet with a thin sheet portion protruding at its center for laser welding to the center of the flip sheet, and a second vent hole for pressure relief on the connecting sheet. The top cover sheet and the boss for use as a positive electrode post are integrally formed, eliminating the need for additional electrode post installation. The flip sheet can function as an explosion-proof valve and is located inside the top cover sheet, avoiding the potential safety risks of exposed explosion-proof valve designs. Overcurrent protection is achieved by using a connecting sheet with a thin sheet portion, solving problems such as insufficient current stability, poor balance between structural strength and function, complex manufacturing processes, and high costs associated with existing connecting sheets.

Description

Technical Field

[0001] This application belongs to the field of battery technology, and particularly relates to a positive electrode top cover assembly of a cylindrical battery and a cylindrical battery. Background Technology

[0002] In the field of cylindrical battery technology, the disclosed positive electrode top cover assembly design typically includes a bare plate structure, on which the electrode post and explosion-proof valve assembly are integrated. However, this assembly design has the following technical problems in practical applications:

[0003] 1. Insufficient process complexity and sealing reliability

[0004] In related technologies, the terminals need to be fixed to the surface of the bare plate through additional processes such as welding and riveting, and insulation and sealing between the terminals and the bare plate are achieved by structures such as sealing rings or laser welding. This design increases the number of manufacturing processes, and the sealing structure is susceptible to environmental factors such as thermal expansion and vibration over a long period of time, which can easily lead to sealing failure or electrolyte leakage, thereby affecting the overall lifespan and safety of the battery.

[0005] 2. Low space utilization and limited module assembly efficiency

[0006] The terminals and explosion-proof valves are both centrally located on the surface of the bare plate, occupying a large lateral space. This results in limited space for welding / riveting the terminals and connecting the terminals when adjacent batteries are assembled in series and / or parallel via connecting tabs (connecting tabs). Irregular designs or increased bridging distances are required to avoid short circuits. This layout not only reduces the module's energy density but also increases the difficulty of module assembly and manufacturing costs.

[0007] 3. Potential safety risks of exposed design of explosion-proof valves

[0008] In related technologies, the explosion-proof valve is directly exposed on the surface of the bare plate, making it susceptible to damage from mechanical impacts or foreign object collisions during transportation and assembly, leading to premature battery failure. Furthermore, when the explosion-proof valve is triggered, the high-temperature, high-pressure substances inside (such as electrolyte and gas) are ejected in a disordered manner, potentially causing short circuits in adjacent batteries, thermal runaway, or even personal injury, posing a higher safety risk, especially in module integration scenarios.

[0009] Therefore, the cylindrical battery positive electrode top cover assembly of the relevant technology has obvious shortcomings in terms of process simplification, space utilization and safety protection performance, and the above technical problems urgently need to be solved through structural optimization. Utility Model Content

[0010] The purpose of this application is to provide a positive electrode top cover assembly for a cylindrical battery and a cylindrical battery, so as to solve at least one of the above-mentioned technical problems.

[0011] To achieve the above-mentioned objectives, the technical solution adopted in this application is as follows:

[0012] This application provides a positive electrode top cover assembly for a cylindrical battery, including:

[0013] The top cover plate has a boss in the middle for use as a positive electrode post. The boss has a first vent hole for pressure relief. The top cover plate and the boss are integrally formed. The boss has a machining hole in the middle for laser welding to extend into.

[0014] The flip plate has a periphery for electrical connection with the inside of the top cover plate, and the edge of the flip plate is also provided with annular grooves.

[0015] The connecting piece is used to connect the battery cell tabs. The middle part of the connecting piece has a protrusion forming a thin sheet for laser welding connection with the middle part of the flip piece. The connecting piece is provided with a second vent hole for pressure relief.

[0016] A ring-shaped insulating element is disposed between the top cover plate and the connecting plate.

[0017] In some embodiments, the periphery of the flip plate is provided with a welding portion, and the inner side of the top cover plate is provided with a stepped portion for connection with the welding portion.

[0018] In some embodiments, the connecting piece is provided with a tab connection portion, which is fan-shaped.

[0019] In some embodiments, the annular insulating element is also located between the weld portion and the tab connection portion.

[0020] This application also provides a cylindrical battery, including the above-described positive electrode top cover assembly.

[0021] Compared with the prior art, the beneficial effects of the embodiments of this application are:

[0022] This application provides a positive electrode top cover assembly and a cylindrical battery. The top cover sheet and the boss used as the positive electrode post are integrally formed, eliminating the need for additional electrode post installation. This not only reduces process complexity but also avoids sealing reliability issues associated with electrode post installation and facilitates series and / or parallel assembly of the battery plates. The flip-over sheet acts as an explosion-proof valve and is located inside the top cover sheet, avoiding the potential safety risks of exposed explosion-proof valve designs. Overcurrent protection is achieved by using a connecting piece with a thin sheet section, rather than through hollowing or removing material. This solves the problems of insufficient current stability, poor balance between structural strength and function, and high manufacturing complexity and cost associated with existing connecting pieces. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A front view of the top cover assembly provided in an embodiment of this application is shown.

[0025] Figure 2 A perspective view of the top cover assembly provided in an embodiment of this application is shown.

[0026] Figure 3 A cross-sectional view of the top cover assembly provided in an embodiment of this application is shown.

[0027] Figure 4 An exploded view of the top cover assembly provided in an embodiment of this application is shown.

[0028] Figure 5 An exploded top view of the top cover assembly provided in an embodiment of this application is shown.

[0029] Figure 6 An exploded bottom view of the top cover assembly provided in an embodiment of this application is shown.

[0030] Figure 7 A front view of the top cover sheet provided in an embodiment of this application is shown.

[0031] Figure 8 A perspective view of the top cover sheet provided in an embodiment of this application is shown.

[0032] Figure 9 A schematic diagram of the structure of the flip sheet provided in an embodiment of this application is shown.

[0033] Figure 10 A schematic diagram of the connecting piece provided in an embodiment of this application is shown.

[0034] Illustration:

[0035] 10. Top cover plate; 11. Stepped part; 12. Boss; 121. First vent hole; 122. Machining hole; 20. Flip piece; 21. Annular groove; 22. Welded part; 30. Annular insulating part; 31. Arc groove; 40. Connecting piece; 41. Thin sheet part; 42. Second vent hole; 43. Arc protrusion; 44. Hollowed-out part; 45. Electrode connecting part. Detailed Implementation

[0036] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0037] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0038] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0039] To illustrate the technical solution described in this application, specific embodiments are provided below.

[0040] Please see Figures 1 to 10 As shown in the figure, this application embodiment provides a positive electrode top cover assembly for a cylindrical battery, including:

[0041] The top cover plate 10 has a boss 12 at its center for use as a positive electrode post. The boss 12 has a first vent hole 121 for pressure relief. The top cover plate 10 and the boss 12 are integrally formed. A machining hole 122 for laser welding is provided in the center of the boss 12. Therefore, no additional hole is needed on the top cover plate 10 to install the positive electrode post.

[0042] The flip plate 20 has its periphery used for electrical connection with the inner side of the top cover plate 10, and its edge is also provided with annular grooves 21. The flip plate 20 can function as an explosion-proof valve and is built into the bottom of the top cover plate 10 to avoid the design risks of an exposed explosion-proof valve.

[0043] The connecting piece 40 is used to connect the battery cell tab. The middle part of the connecting piece 40 has a protrusion forming a thin sheet 41 for laser welding connection with the middle part of the flip piece 20. The connecting piece 40 has a second vent hole 42 for pressure relief.

[0044] An annular insulating element 30 is disposed between the top cover plate 10 and the connecting plate 40.

[0045] Therefore, during assembly, the top cover plate 10 and the flip plate 20 are first connected as one piece, and then the annular insulating part 30 is placed between the top cover plate 10 and the connecting piece 40. The laser welding equipment realizes the laser welding between the thin sheet 41 and the flip plate 20 through the processing hole 122.

[0046] Therefore, during use, when overcurrent heating or excessive internal battery pressure occurs, the middle portion of the flip piece 20 (i.e., the part connected to the thin sheet 41) flips upward, causing the thin sheet 41 to tear, thereby disconnecting the electrical connection between the connecting piece 40 and the flip piece 20, thus achieving overcurrent protection and preventing excessive internal pressure. If the internal battery pressure further increases after the thin sheet 41 tears, the annular notch 21 of the flip piece 20 tears, further releasing pressure.

[0047] As an example, the thickness of the sheet portion 41 is 0.03 mm to 0.2 mm.

[0048] As an example, the connecting piece 40 also has a cutout 44 for saving material, thereby achieving weight reduction and cost reduction.

[0049] As an example, the bottom of the annular insulating member 30 is provided with an arc-shaped groove 31, and the top of the connecting piece 40 is provided with an arc-shaped protrusion 43 for embedding into the arc-shaped groove 31, so as to achieve concentric positioning during assembly.

[0050] The aforementioned positive electrode top cover assembly features a top cover plate 10 and a boss 12 used as a positive electrode post, all integrally formed. This eliminates the need for additional electrode post installation, reducing process complexity, avoiding sealing reliability issues associated with electrode post installation, and facilitating series and / or parallel assembly of the electrodes. The flip plate 20 functions as an explosion-proof valve and is located inside the top cover plate 10, avoiding the potential safety risks of exposed explosion-proof valve designs. Overcurrent protection is achieved by using a connecting plate 40 with a thin sheet portion 41, rather than through hollowing or material removal. This solves problems such as insufficient current stability, poor balance between structural strength and function, and high manufacturing complexity and cost associated with existing connecting plates.

[0051] As an example, the periphery of the flip plate 20 is provided with a welding portion 22, and the inner side of the top cover plate 10 is provided with a stepped portion 11 for connecting with the welding portion 22.

[0052] As an example, the connecting piece 40 is provided with a tab connecting portion 45, which is fan-shaped.

[0053] As an example, the annular insulating element 30 is also located between the welded portion 22 and the tab connection portion 45.

[0054] In some embodiments of this application, a cylindrical battery is also provided, including the above-described positive electrode top cover assembly, which also has the aforementioned beneficial effects.

[0055] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A positive electrode top cover assembly for a cylindrical battery, characterized in that, include: The top cover plate has a boss in the middle for use as a positive electrode post, and a first vent hole for pressure relief is provided on the boss. The top cover plate and the boss are integrally formed, and a machining hole for laser welding to extend into is provided in the middle of the boss. A flip-up piece, the periphery of which is used for electrical connection with the inner side of the top cover piece, and the edge of the flip-up piece is also provided with annular grooves; A connecting piece is used to connect the battery cell tabs. The middle part of the connecting piece has a protrusion forming a thin sheet portion for laser welding connection with the middle part of the flip piece. A second vent hole for pressure relief is provided on the connecting piece. An annular insulating element is disposed between the top cover plate and the connecting plate.

2. The positive electrode top cover assembly according to claim 1, characterized in that, The periphery of the flip plate is provided with a welding part, and the inner side of the top cover plate is provided with a stepped part for connecting with the welding part.

3. The positive electrode top cover assembly according to claim 2, characterized in that, The connecting piece is provided with a tab connection part, which is in the shape of a fan ring.

4. The positive electrode top cover assembly according to claim 3, characterized in that, The annular insulating component is also located between the welded portion and the tab connection portion.

5. A cylindrical battery, characterized in that, Includes the positive electrode top cover assembly as described in any one of claims 1 to 4.

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