Safety over-charge prevention cover board for ternary lithium battery

Abstract

The invention provides a safety over-charge prevention cover board for a ternary lithium battery, which comprises a cover board main body, a bottom insulation board, and a positive terminal and a negative terminal which are respectively and fixedly arranged at the upper end face of the cover board main body. The positive terminal is conducted with the cover board main body; an insulating mat is arranged between the negative terminal and the cover board main body; the bottom end face of the negative terminal is connected with a temperature sensor for sensing an internal temperature of the lithium battery; a liquid conducting medium is arranged at the bottom of the temperature sensor; and when the internal temperature of the battery is excessively high, the liquid conducting medium is expanded to ascend to the top end of the battery, so that the negative terminal is conducted with the cover board main body to form an external short circuit. When an over-charge temperature of the battery is risen, the liquid conducting medium is expanded to change the temperature sensor into a conductor, so that the negative terminal is conducted with the cover board to form the external short circuit, thereby preventing thermal runaway in the over-charge process and ensuring over-charge safety of the battery.

Description

[0001] technical field [0002] The invention relates to the technical field of lithium ion batteries, in particular to a safety overcharge prevention cover plate for a ternary lithium battery. Background technique [0003] With the development of ternary material lithium batteries and the improvement of battery energy density, a single measure of adding anti-overcharge electrolyte additives or a simple cover plate structure can no longer meet the needs of ternary battery safety performance and cycle life. In view of the requirements of the overcharge test in the safety performance test of the ternary battery, the problem of improving the safety of the overcharge test on the structure of the ternary battery needs to be solved urgently. At present, the cover plate of ordinary lithium battery basically has no anti-overcharge structure. Most of the anti-overcharge methods of the battery are to add electrolyte additives. The anti-overcharge electrolyte additives used will genera...

AI Technical Summary

Problems solved by technology

At present, the cover plate of ordinary lithium battery basically has no anti-overcharge structure. Most of the anti-overcharge methods of the battery are to add electrolyte additives. The anti-overcharge electrolyte additives used will generate gas when the battery is overcharged, causing the battery to bulge. Affect battery pack

At the same time, the anti-overcharge electrolyte additive has certain side effects on the cycle performance of the battery and affects the performance of the electrical performance.

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