Lithium battery and preparation method thereof

Abstract

The invention relates to the field of batteries, and provides a lithium battery and a preparation method thereof. The lithium battery comprises a positive current collecting disc, a roll core, a shelland an explosion-proof sheet, wherein the positive current collecting disc comprises a disc body, a first boss and a first groove; the roll core is formed by winding a positive plate, a negative plate and a diaphragm, so that the positive plate is wrapped by the negative plate, the negative plate is wrapped by the diaphragm, the back surface of the first groove is pressed into the positive exposed foil of the roll core, and the joint of the first groove and the positive electrode is welded; the bottom of the shell is provided with a plurality of second grooves which are formed at intervals and are sunken towards the opening of the shell, and the roll core is arranged in the shell, so that the negative electrode of the roll core is attached to the second grooves, and the attachment positions of the negative electrode of the roll core and the second grooves are welded; the explosion-proof sheet comprises a platform protruding outwards towards one side of the positive current collectingdisc and a pressing sheet surrounding the periphery of the platform, nicks are formed at the joint of the pressing sheet and the platform, and the bottom surface of the platform makes contact with andis welded to the first boss. According to the invention, super-high-rate charging and discharging can be carried out, and the required high-current discharging requirement is met.

Description

technical field [0001] The invention relates to the technical field of batteries, in particular to a lithium battery and a preparation method of the lithium battery. Background technique [0002] At present, lithium batteries are developing rapidly, especially in the fields of electric vehicles, electric bicycles, and electric motorcycles. As a battery used in electric vehicles, the requirements for its rate performance continue to increase, especially when it is used as a starting power supply and when an electric vehicle accelerates and climbs a slope to provide high-current discharge. At present, lithium battery structures mainly include single-tab structure, multi-tab structure and all-tab structure. [0003] Single tab and multi-tab structures are mainly welded from the edge or middle of the positive and negative current collectors (copper, aluminum strips), and welded to the shell and cap through the tabs. For batteries with this structure, the size of the tabs is re...

AI Technical Summary

Problems solved by technology

Compared with single tab and multi-tab structures, the rate performance of this structure has been greatly improved. However, due to the size of the resistance welding area and the size of the metal sheet, the battery still cannot meet the high rate discharge requirements.

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