Non-water electrolyte for high-voltage lithium ion battery and preparation method

Abstract

The invention relates to non-water electrolyte for a high-voltage lithium ion battery and a preparation method. The non-water electrolyte is characterized in that: respectively purifying sulphone compound, halogenated cyclic carbonic ester and carbonic ester through rectification and molecular sieving under the protection of argon or nitrogen; mixing the sulphone compound, the halogenated cyclic carbonic ester and the carbonic ester in the weight ratio of 1:1:2 to obtain a non-water mixed solvent from which impurities and water are removed; dissolving 10 to 18 percent of mixed lithium salt in 80 to 87 percent of non-water mixed solvent to obtain the electrolyte; adding 2 to 5 percent of additive into the electrolyte; and uniformly mixing at the temperature of 40 DEG C to obtain the non-water electrolyte for a 4.8 Vvs.Li+ / Li lithium ion battery. The electrolyte has higher compatibility with a cathode material under high voltage and can form a stable solid electrolyte interface (SEI) film on the surfaces of a positive electrode and a negative electrode. Besides, the invention has the advantages that: the preparation process is simple, and the method is easy to implement and suitable for industrialized production.

Description

technical field [0001] The invention relates to a non-aqueous electrolytic solution of a lithium ion battery, specifically a high-voltage non-aqueous electrolytic solution of a lithium ion battery, belonging to the field of battery materials. [0002] The invention also relates to a preparation method of the lithium ion battery electrolyte. Background technique [0003] As a new generation of green and high-efficiency batteries, lithium-ion batteries are widely used in portable electronic devices such as mobile phones, notebook computers, and digital cameras due to their advantages of high voltage, high energy density, long cycle life, light weight, and no memory effect. However, with the rapid development of high-performance and multi-functional portable devices, higher requirements are placed on the capacity and energy density of lithium-ion batteries. [0004] Improving the working voltage of lithium-ion is considered to be the most effective way to increase its energy d...

AI Technical Summary

Problems solved by technology

[0006] Sulfone-based electrolytes have high oxidation stability. Xiaoguang Sun [Electrochemistry Communications 11, 2009 1418-1421] found that lithium-ion batteries using pure sulfone-based electrolytes have high stable potential, but poor cycle performance. The cycle performance of the battery with VC additive is greatly improved

A. Abouimrane [Electrochemistry Communications 11, 2009 1073-1076] believes that the pure sulfone-based electrolyte cannot meet the infiltration of the battery diaphragm, and the lithium-ion battery electrolyte system using a mixture of sulfone and carbonate has good performance in the low voltage range. cycle stability, but the author did not test the performance of the electrolyte in the high voltage region

[0007] In previous studies, various problems aimed at solving the cycle performance degradation and safety performance degradation at high voltage of the battery have been proposed.