Wide-temperature-range electrolyte of lithium ion battery

Abstract

The invention discloses a wide-temperature-range electrolyte of a lithium ion battery. The electrolyte comprises an electrolyte salt and an organic solvent, wherein the electrolyte salt comprises bis(pinyl) borate lithium. The structural general formula of the bis (pinyl) borate lithium is represented by the general formula (I) and shown in the discription. In the general formula (I), R1 to R8 are independently selected from hydrogen atom, halogen atom, substituted or unsubstituted C1-6 alkyl group, substituted or unsubstituted C1-6 olefin, substituted or unsubstituted C1-6 alkoxy group, sulfonyl group, sulfone and substituted or unsubstituted C6-C20 aryl group. The electrolyte provided by the invention has the characteristics of low melting point, low viscosity, high conductivity, high thermal stability and high chemical stability. Moreover, the electrolyte is high in low-temperature discharge inflection point voltage, high in discharge platform and high in capacity, and has good high-temperature storage capacity retention rate and recovery rate.

Description

technical field [0001] The invention belongs to the field of lithium ion batteries, and relates to a wide temperature range electrolyte solution for lithium ion batteries. Background technique [0002] Lithium-ion batteries are widely used in 3C digital and new energy transportation fields because of their advantages such as high energy density, high power, long cycle, and environmental protection. However, lithium-ion batteries are affected by the performance of the electrolyte, and there are problems such as insufficient low-temperature discharge performance, high-temperature self-discharge, and poor thermal stability at high temperatures, which seriously restrict its development. Therefore, there is still a need to develop a lithium-ion battery electrolyte to improve the performance of lithium-ion batteries. [0003] Lithium hexafluorophosphate is currently the most widely used electrolyte salt for lithium-ion batteries. Lithium hexafluorophosphate has a small fluorine ...

AI Technical Summary

Problems solved by technology

However, bis(pinacyl) borate lithium salt has its own disadvantages. Under high potential, it will cause serious corrosion to the aluminum foil of the positive current collector, resulting in dense small holes in the current collector of the aluminum foil, the electrode powder will fall, and the aluminum foil will be exposed. , affecting the safety performance of lithium-ion batteries

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