Large cylindrical lithium battery positive collector plate and welding method thereof

Abstract

The invention discloses a large cylindrical lithium battery positive collector plate and a welding method thereof. The large cylindrical lithium battery positive collector plate comprises a positive collector plate, a directional fusing gap, a roll core, an extension handle and a cap aluminum plate, the positive current collecting disc is made of 1060-O; the directional fusing gap is arranged on the extension handle, and the directional fusing gap is positioned on one side, close to the cap aluminum plate after the extension handle is bent, far away from the positive electrode end face diaphragm and a central hole diaphragm pre-rolling position; the corner of a welding track is in smooth transition, so that anomalies such as short circuit of the roll core caused by the fact that laser welding heat is concentrated to burn through a diaphragm are prevented; and a feeding fool-proof hole is formed in the positive current collecting disc. The directional fusing gap is designed at the extension handle of the positive collector plate, the extension handle is fused at the appointed design position close to one side of the cap when the battery is subjected to external short circuit, and the fusing position is far away from the diaphragm, so that the hidden danger of thermal runaway uncontrollability caused by internal short circuit due to diaphragm shrinkage caused by high temperature is prevented.

Description

Technical Field

[0001] The invention relates to the technical field of lithium battery positive current collector plates, and in particular to a large cylindrical lithium battery positive current collector plate and a welding method thereof. Background Art

[0002] The existing large cylindrical lithium battery has a full-ear structure, and the positive collector plate extension handle is welded to the cap aluminum plate. The battery is sealed after the extension handle is bent into the shell. The extension handle mainly bears the battery's overcurrent capacity. When the finished battery is abused during use, causing an external short circuit, the battery current will increase instantly. When the overcurrent capacity of the positive extension handle is exceeded, the extension handle will melt and the battery will be disconnected to prevent explosions and other dangerous situations. In existing batteries, when the battery is short-circuited, the extension handle does not have a fixed fuse position. If it is close to the collector plate, the high temperature will cause the diaphragm to shrink and the positive and negative electrodes to contact, causing an internal short circuit, which may lead to thermal runaway and pose a great safety hazard. Summary of the invention

[0003] Based on the technical problems existing in the background technology, the present invention proposes a positive current collector of a large cylindrical lithium battery and a welding method thereof. A directional fuse notch is designed at the extension handle of the positive current collector. The cross-sectional area at the notch is small and the current capacity is weak. After the extension handle is welded and bent into the shell with the cap aluminum plate, the fuse notch at the extension handle is close to one side of the cap aluminum plate. When an external short circuit occurs in the battery, the internal current rises and the temperature rises, and a directional fuse is performed at the designed fuse notch. After the extension handle is bent, the notch is close to the cap side and away from the diaphragm to avoid abnormal shrinkage of the diaphragm due to excessive temperature.

[0004] The present invention provides a positive current collector for a large cylindrical lithium battery, comprising a positive current collector, a directional fuse notch, a winding core, an extension handle and a cap aluminum plate; The positive collector plate is made of 1060-O; The directional fuse notch is arranged on the extension handle, and the directional fuse notch is located at a side of the extension handle close to the cap aluminum plate after the extension handle is bent, away from the positive terminal diaphragm and the pre-rolled part of the center hole diaphragm; The positive collector is welded to the positive end of the winding core, and the corners of the welding track are smoothly transitioned to prevent the laser welding heat from burning through the diaphragm and causing abnormalities such as short circuit of the winding core; The positive current collecting disc is provided with a feeding fool-proof hole, and the CCD recognition system can identify the front and back sides of the current collecting disc when the current collecting disc is automatically fed, thereby preventing the current collecting disc from being reversely welded to the positive end of the winding core.

[0005] A welding method for a positive current collector of a large cylindrical lithium battery comprises the following steps: S1: The positive collector plate is laser welded to the positive end of the winding core; the negative collector plate is laser welded to the negative end of the winding core; S2: The positive end of the winding core is covered with an insulating sheet, wrapped with high-temperature tape, and the winding core is put into the shell; S3: After the shell is put in, the core is welded at the bottom, the shell is grooved, and the core is baked and then injected with liquid; S4: After the liquid is injected, the positive collector plate is welded to the cap aluminum plate, and the positive collector plate is bent into the shell; S5: The core is sealed. After sealing, the directional fuse notch on the extension handle of the positive collector is on one side of the cap aluminum plate; S6: After sealing, the core rolls undergo subsequent production processes.

[0006] The beneficial effects of the present invention are as follows: a directional fuse notch is designed at the extension handle of the positive current collecting disk, so that when an external short circuit occurs in the battery, the extension handle is allowed to fuse at a designated design position close to the cap side, and the fuse position is far away from the diaphragm, thereby preventing the high temperature from causing the diaphragm to shrink and cause an internal short circuit, thereby preventing the hidden danger of uncontrollable thermal runaway. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 It is a schematic diagram of the structure after the extension handle is bent in the present invention; Figure 3 It is a schematic diagram of the structure of the lithium battery and the cap aluminum plate in the present invention; Figure 4 It is a structural schematic diagram of the positive collecting plate, the cap aluminum plate welding wire and the cap in the present invention.

[0008] In the figure: 1. Positive current collector; 2. Directional fuse notch; 3. Welding track; 4. Notch; 5. Feeding anti-fool hole; 6. Winding core; 7. Extension handle; 8. Lithium battery; 9. Cap aluminum plate; 10. Welding wire between positive current collector and cap aluminum plate; 11. Cap. DETAILED DESCRIPTION

[0009] The present invention will be further explained below in conjunction with specific embodiments. Example

[0010] refer to Figure 1-4 In this embodiment, a positive current collector of a large cylindrical lithium battery is proposed, including a positive current collector 1, a directional fuse notch 2, a winding core 6, an extension handle 7 and a cap aluminum plate 9; The positive current collecting plate 1 is made of 1060-O; The directional fuse notch 2 is arranged on the extension handle 7, and the directional fuse notch 2 is located on the side of the extension handle 7 close to the cap aluminum plate 9 after the extension handle 7 is bent, away from the positive terminal diaphragm and the center hole diaphragm pre-roll; The positive collector plate 1 is welded to the positive end of the winding core 6; the welding track is as follows: Figure 1 As shown in the figure, the corners of the welding track are smoothly transitioned to prevent the laser welding heat from burning through the diaphragm and causing abnormalities such as short circuit of the winding core; The positive current collecting disc 1 is provided with a feeding fool-proof hole 5; when the current collecting disc is automatically fed, the CCD recognition system can identify its front and back sides to prevent the current collecting disc from being reversely welded to the positive end of the winding core.

[0011] A welding method for a positive current collector of a large cylindrical lithium battery comprises the following steps: S1: The positive collector plate 1 is laser welded to the positive end of the winding core 6; the negative collector plate is laser welded to the negative end of the winding core 6; S2: The positive end of core 6 is covered with an insulating sheet and a high-temperature tape, and core 6 is put into the shell; S3: After the shell is put in, the core is welded at the bottom at 6 points, the shell is grooved, and the core 6 is baked and then filled with liquid; S4: After the liquid is injected, the positive collecting plate 1 is welded to the cap aluminum plate 9, and the positive collecting plate 1 is bent into the shell; S5: The winding core 6 is sealed. After sealing, the directional fuse notch 2 on the extension handle 7 of the positive current collecting plate 1 is on one side of the cap aluminum plate 9; S6: After sealing, the core 6 undergoes subsequent production processes.

[0012] It can be seen from the above-mentioned large cylindrical positive current collector and welding method that the present invention proposes a novel large cylindrical battery positive current collector, a directional fuse notch 2 is designed at the extension handle 7 of the positive current collector 1, the cross-sectional area of ​​the directional fuse notch 2 is small and the current carrying capacity is weak, after the extension handle 7 is welded and bent into the shell with the cap aluminum plate 9, the directional fuse notch 2 at the extension handle 7 is close to the side of the cap aluminum plate 9 away from the positive end surface diaphragm and the center hole diaphragm pre-roll, when an external short circuit occurs in the lithium battery 8, the internal current increases and the temperature increases, and a directional fuse is performed at the designed directional fuse notch 2, and after the extension handle 7 is bent, the directional fuse notch 2 is close to the side of the cap 11 to avoid abnormal diaphragm shrinkage caused by excessive temperature.

[0013] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A positive current collector for a large cylindrical lithium battery, characterized in that: It comprises a positive current collecting plate (1), a directional fuse notch (2), a winding core (6), an extension handle (7) and a cap aluminum plate (9); The positive collecting plate (1) is made of 1060-O; The directional fuse notch (2) is arranged on the extension handle (7), and the directional fuse notch (2) is located on the side of the extension handle (7) close to the cap aluminum plate (9) after being bent, away from the positive terminal diaphragm and the center hole diaphragm pre-rolled position; The positive current collecting disc (1) is welded to the positive end of the winding core (6); The positive current collecting plate (1) is provided with a loading anti-fool hole (5).

2. A welding method for a positive current collector of a large cylindrical lithium battery as claimed in claim 1, characterized in that: The following steps are involved: S1: The positive current collecting disc (1) and the positive end of the winding core (6) are laser welded; the negative current collecting disc and the negative end of the winding core (6) are laser welded; S2: The positive end of the winding core (6) is covered with an insulating sheet and a high-temperature tape, and the winding core (6) is placed in a shell; S3: After the shell is put into the roll core (6), the bottom of the roll core (6) is welded, the shell is grooved, and the roll core (6) is baked and then injected with liquid; S4: After the liquid is injected, the positive current collecting plate (1) is welded to the cap aluminum plate (9), and the positive current collecting plate (1) is bent into the shell; S5: the winding core (6) is sealed. After the sealing, the directional fuse notch (2) on the extension handle (7) of the positive collector plate (1) is on one side of the cap aluminum plate (9); S6: After sealing, the core (6) undergoes subsequent production processes.

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