Electrolyte for improving cycle performance of anode materials of lithium-ion batteries

Abstract

The invention discloses an electrolyte for improving cycle performance of anode materials of lithium-ion batteries. The electrolyte comprises an organic solvent, lithium salt and an additive, wherein the additive is TTFEB (tri-(2,2,2-trifluoroethyl)borate), and the organic solvent comprises cyclic carbonate and linear carbonate. The added additive, namely, the TTFEB, of the electrolyte facilitates formation of stable SEI films on anode surfaces, prevents co-embedment of solvent molecules, and inhibits further reactions of anodes and the electrolyte. Meanwhile, through addition of the TTFEB, the composition of the SEI films can be improved, inert components such as LiF, Li2O, Li2O2 and the like are promoted, film impedance is reduced, polarization is reduced, and consumption of the lithium-ions is reduced. The TTFEB has an improving effect on the SEI films of the anodes, so that the electrolyte containing the TTFEB can effectively improve the cycle performance of the anode materials, the charging and discharging efficiency and the rate capability.

Description

technical field [0001] The invention belongs to the field of lithium ion batteries and relates to an electrolyte solution for improving the cycle performance of carbon negative electrodes, graphite negative electrodes, silicon-based negative electrodes and tin-based negative electrodes. Background technique [0002] With the development of human society, traditional fossil energy sources such as oil and natural gas continue to be exhausted, and people are paying more and more attention to environmental protection issues. It is imminent to develop new green and environmentally friendly energy sources and new and efficient energy storage technologies. Lithium-ion batteries have the advantages of small size, high energy density, high working voltage, long cycle life, environmental friendliness, no memory effect and small self-discharge, so they are widely used in portable electronic devices such as mobile phones, digital cameras, and notebook computers. With the advancement of ...

AI Technical Summary

Problems solved by technology

At present, the modification of the surface film of the electrode is mainly realized by modifying the negative electrode and the electrolyte. Among them, the modification and coating of the negative electrode, mechanical grinding, surface film formation and other methods are complicated in process, low in repeatability, and high in cost.

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