Cylindrical battery collector plate and welding method thereof

Abstract

The invention discloses a cylindrical battery collector plate and a welding method thereof, and relates to the technical field of new energy batteries, the cylindrical battery collector plate comprises a collector plate body, an extension handle, a cap welding area, a battery shell, a roll core and a cap, the roll core is provided with a roll core center hole, the cap welding area is provided with a first through hole, the middle part of the extension handle is provided with a second through hole, and the cap welding area is provided with a second through hole. A third through hole is formed in the collector plate body; the first through hole, the second through hole and the third through hole are folded and assembled in a Z shape on the collector plate body to form an air flow conduction channel; the diameter of the first through hole is larger than that of the cap, the diameter of the second through hole is larger than that of the first through hole and that of the third through hole, the welding track is annular, the welding area is larger, the current distribution on the cover plate is more uniform, the heat dissipation performance in the battery can be effectively improved, the temperature rise of the battery during high-rate charging and discharging is reduced, and the service life of the battery is prolonged. The safety and the service life of the battery are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy batteries, and in particular to a cylindrical battery current collecting plate and a welding method thereof. Background Art

[0002] With the continuous optimization of material technology, manufacturing processes, and structural design, large-size cylindrical batteries have significant advantages in manufacturing cost, energy density, and power output. They will play a greater role in electric vehicles, energy storage systems, and other fields in the future. However, as the size of cylindrical batteries increases, the battery's current conductivity and safety performance requirements will also increase. The collector plate is a key component that connects the winding core tab and cap inside the lithium battery. Its structure and welding quality directly affect the battery's performance and safety.

[0003] A common current collector plate consists of three parts: the collector plate body, an extension handle, and a cap welding area. The extension handle and cap welding area are usually designed with a flat plate structure. However, during the assembly process, the extension handle is prone to bending and deformation, resulting in misalignment when welding with the cap, which in turn affects the assembly quality. In addition, after the current collector plate is bent, the extension handle will block the center hole of the winding core, hindering the rapid and directional discharge of internal gas from the battery through the explosion-proof valve during thermal runaway, increasing the risk of the cover plate exploding. To this end, we propose a cylindrical battery collector plate and its welding method to solve the above problems. Summary of the Invention

[0004] The purpose of this application is to provide a cylindrical battery current collector and welding method thereof to address the problem, raised in the aforementioned background art, that the extension handle is prone to bending and deformation during assembly, resulting in misalignment during welding with the cap, which in turn affects assembly quality. Furthermore, when the current collector is bent, the extension handle blocks the central hole of the winding core, hindering the rapid and directional discharge of internal battery gas through the explosion-proof valve in the event of thermal runaway, increasing the risk of the cover plate rupturing.

[0005] To achieve the above-mentioned objectives, the present application provides the following technical solutions: a cylindrical battery current collector, comprising a current collector body, an extension handle, a cap welding area, a battery shell, a winding core and a cap, wherein the winding core is provided with a winding core center hole, the cap welding area is provided with a first through hole, the middle part of the extension handle is provided with a second through hole, and the current collector body is provided with a third through hole.

[0006] Preferably, the first through hole, the second through hole and the third through hole form an airflow conducting channel after the collecting plate body is assembled in a Z-shaped folding manner.

[0007] Preferably, the aperture of the first through hole is larger than the aperture of the cap, the aperture of the second through hole is larger than the apertures of the first through hole and the third through hole, and the aperture of the third through hole is larger than the aperture of the central hole of the winding core.

[0008] Preferably, the cross-sectional shape of the airflow guiding channel is one of circular, elliptical, square and triangular.

[0009] Preferably, the collecting plate body, the extension handle and the cap welding area are made of an integral molding process, and the material is one of copper, aluminum and nickel.

[0010] Preferably, the apertures of the first through hole, the second through hole and the third through hole range from 1 mm to 12 mm.

[0011] The present invention also proposes a welding method for a cylindrical battery collector plate, comprising the following steps: S1: Laser welding is used to weld the collector plate body and the winding core tab welding area; S2: Using laser welding process to weld the cap welding area and the cap; S3: folding the collecting plate body, the extension handle, and the cap welding area in a Z-shape to align the first through hole, the second through hole, and the third through hole to form an airflow channel; S4: The welding positions of the collector plate body and the winding core should be evenly distributed, using one of the shapes of point, straight line, spiral, sine line, broken line and wave line; S5: The welding position of the cap welding area and the cap is around the first through hole, forming a circular ring around the first through hole, and the welding trajectory adopts one of the shapes of point, straight line, spiral, sine line, broken line and wave line; S6: The parameters of the laser welding process are: laser power 100W-500W, welding speed 100mm / s-800mm / s, and defocus 0mm-2mm.

[0012] The beneficial effects of the present invention are: 1. Through holes are provided in the collector plate extension handle, the welding area between the collector plate body and the winding core tab, and the cap welding area. After Z-shaped folding assembly, a continuous airflow channel is formed to ensure that the internal gas of the battery can be quickly and directionally discharged through the explosion-proof valve in the event of thermal runaway, thereby significantly improving the safety performance of the battery. 2. A through-hole is provided at the connection end of the collector plate extension handle and the cover plate, which can be used for physical positioning during laser welding to ensure the concentricity of the welding between the collector plate and the cover plate. This can effectively prevent the extension handle from bending and contacting the battery case due to welding deviation, causing a short circuit, thereby affecting the battery safety performance. 3. This welding method has a circular welding track, a larger welding area, and a more uniform current distribution on the cover, which can effectively improve the heat dissipation performance inside the battery, reduce the temperature rise of the battery during high-rate charge and discharge, and improve the safety and service life of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1This is a schematic structural diagram of a current collecting plate according to an embodiment of the present application; Figure 2 This is a schematic diagram of the Z-folded current collecting plate structure of an embodiment of the present application; Figure 3 This is a structural cross-sectional view of a battery housing according to an embodiment of the present application; Figure 4 This is an enlarged structural view of a cross section of a battery housing according to an embodiment of the present application; Figure 5 Schematic diagram of the structure of the current collecting plate with different through-hole shapes according to the embodiment of the present application.

[0014] In the figure: 1. Collecting plate body; 2. Extension handle; 3. Cap welding area; 4. First through hole; 5. Second through hole; 6. Third through hole; 7. Battery housing; 8. Winding core; 9. Winding core center hole; 10. Cap. DETAILED DESCRIPTION

[0015] The present invention will be further explained below with reference to specific embodiments.

[0016] refer to Figure 1-Figure 5 In this embodiment, a cylindrical battery current collector is proposed, including a current collector body 1, an extension handle 2, a cap welding area 3, a battery shell 7, a winding core 8 and a cap 10. The winding core 8 is provided with a winding core center hole 9, the cap welding area 3 is provided with a first through hole 4, the middle of the extension handle 2 is provided with a second through hole 5, and the current collector body 1 is provided with a third through hole 6.

[0017] With the above structure, in order to ensure that the air flow passage of the core center hole 9 is unobstructed, the first through hole 4, the second through hole 5, the third through hole 6, the core center hole 9 and the explosion-proof valve on the cap 10 are in the same straight line.

[0018] In this embodiment, the first through hole 4, the second through hole 5 and the third through hole 6 form an airflow conducting channel after the collecting plate body 1 is folded and assembled in a Z shape.

[0019] In this embodiment, the aperture of the first through hole 4 is greater than or equal to the aperture of the cap 10, the aperture of the second through hole 5 is greater than or equal to the apertures of the first through hole 4 and the third through hole 6, and the aperture of the third through hole 6 is greater than or equal to the aperture of the core center hole 9.

[0020] In this embodiment, the cross-sectional shape of the airflow guiding channel is one of circular, elliptical, square and triangular.

[0021] In this embodiment, the collecting plate body 1 , the extending handle 2 and the cap welding area 3 are made by an integrated molding process, and the material is one of copper, aluminum and nickel.

[0022] In this embodiment, the diameters of the first through hole 4 , the second through hole 5 and the third through hole 6 range from 1 mm to 12 mm.

[0023] In this embodiment, in order to ensure the mechanical strength of the extension handle 2, reinforcing ribs may be provided on both sides of the through hole of the extension handle 2 to prevent deformation.

[0024] In this embodiment, in order to prevent burrs on the edge of the extension handle 2 , an arc design is made on the edge of the extension handle 2 .

[0025] The present invention also proposes a welding method for a cylindrical battery collector plate, comprising the following steps: S1: Using laser welding process to weld the collector plate body 1 and the tab welding area of the winding core 8; S2: welding the cap welding area 3 and the cap 10 using a laser welding process; S3: fold the collecting plate body 1, the extension handle 2 and the cap welding area 3 in a Z-shape to align the first through hole 4, the second through hole 5 and the third through hole 6 to form an airflow channel; S4: The welding positions of the collecting plate body 1 and the winding core 8 should be evenly distributed, and adopt one of the shapes of point, straight line, spiral, sine line, broken line and wave line; S5: The welding position of the cap welding area 3 and the cap 10 is around the first through hole 4, forming a circular ring around the first through hole 4, and the welding trajectory adopts one of the shapes of point, straight line, spiral, sine line, broken line and wave line; S6: The parameters of the laser welding process are: laser power 100W-500W, welding speed 100mm / s-800mm / s, and defocus 0mm-2mm.

[0026] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A cylindrical battery collector plate, characterized in that: The battery comprises a current collecting disc body (1), an extension handle (2), a cap welding area (3), a battery housing (7), a winding core (8) and a cap (10), wherein the winding core (8) is provided with a winding core center hole (9), the cap welding area (3) is provided with a first through hole (4), the middle of the extension handle (2) is provided with a second through hole (5), and the current collecting disc body (1) is provided with a third through hole (6).

2. A cylindrical battery current collecting tray according to claim 1, characterized in that: The first through hole (4), the second through hole (5) and the third through hole (6) form an airflow conduction channel after the collecting plate body (1) is assembled in a Z-shaped folding manner.

3. A cylindrical battery current collecting tray according to claim 1, characterized in that: The aperture of the first through hole (4) is larger than the aperture of the cap (10), the aperture of the second through hole (5) is larger than the apertures of the first through hole (4) and the third through hole (6), and the aperture of the third through hole (6) is larger than the aperture of the core center hole (9).

4. A cylindrical battery current collecting tray according to claim 1, characterized in that: The cross-sectional shape of the airflow guiding channel is one of circular, elliptical, square and triangular.

5. The cylindrical battery current collecting tray according to claim 1, characterized in that: The collecting disc body (1), the extension handle (2) and the cap welding area (3) are manufactured using an integrated molding process, and the material is one of copper, aluminum and nickel.

6. The cylindrical battery current collecting tray according to claim 1, characterized in that: The apertures of the first through hole (4), the second through hole (5) and the third through hole (6) range from 1 mm to 12 mm.

7. A welding method for a cylindrical battery collector plate, characterized in that: The following steps are involved: S1: using a laser welding process to weld the collector plate body (1) and the tab welding area of the winding core (8); S2: welding the cap welding area (3) and the cap (10) using a laser welding process; S3: assembling the collecting plate body (1), the extension handle (2) and the cap welding area (3) in a Z-shaped folding manner so that the first through hole (4), the second through hole (5) and the third through hole (6) are aligned to form an airflow conduction channel; S4: The welding positions of the collecting plate body (1) and the winding core (8) should be evenly distributed and adopt one of the shapes of point, straight line, spiral, sinusoidal line, broken line and wave line; S5: The welding position of the cap welding area (3) and the cap (10) is around the first through hole (4), forming a circular ring around the first through hole (4), and the welding trajectory adopts one of the shapes of point, straight line, spiral, sine line, broken line and wave line; S6: The parameters of the laser welding process are: laser power 100W-500W, welding speed 100mm / s-800mm / s, and defocus 0mm-2mm.

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