Electrolyte and secondary battery

Abstract

The invention provides an electrolyte and a secondary battery. The electrolyte comprises electrolyte salt, organic solvents and additives; the additives comprise one or multiple in the compounds as shown in formula. After the electrolyte of the invention is applied to the secondary battery, the normal temperature and low temperature cycle performance, the high temperature storage performance and the hotbox security performance can be effectively improved.

Description

technical field [0001] The invention relates to the technical field of batteries, in particular to an electrolyte and a secondary battery. Background technique [0002] In recent years, with the rapid development of secondary batteries, especially lithium-ion secondary batteries, in the field of portable electrical appliances, there is an increasing demand for small, lightweight, thin and high-performance secondary batteries that provide power for these portable electronic devices Increase. Due to the continuous pursuit of high energy density of secondary batteries, the use of positive and negative electrodes with high compaction density or negative electrode materials with high capacity but poor cycle performance is a strategy commonly used in the industry at present. The resulting problem is that the electrolyte cannot fully infiltrate the electrodes, resulting in an increase in the charge platform of the secondary battery and a decrease in the discharge platform, which a...

AI Technical Summary

Problems solved by technology

Taking the charging and discharging process of lithium-ion secondary batteries as an example, a dense, uniform and stable SEI film can ensure the cycle performance of lithium-ion secondary batteries. The film is in barrier-free contact and chemical and electrochemical reactions occur, causing the organic solvent to be consumed infinitely, resulting in a sudden decrease in the cycle life of the lithium-ion secondary battery

At low temperature, the formed SEI film is too thick, and the impedance is too high, so that lithium ions cannot migrate through, which greatly reduces the capacity retention rate of lithium-ion secondary batteries after cycling.

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