High voltage lithium-ion battery electrolyte and lithium-ion battery

Abstract

The invention discloses a high voltage lithium-ion battery electrolyte which is composed of an electrolyte solute, a solvent and an additive agent, wherein the additive agent comprises a positive electrode film formation additive agent and a conventional additive agent; the positive electrode film formation additive agent is at least one selected from HFiP, PFBP and Al (HFiP); the conventional additive agent is one or more selected from VC, FEC, VEC, 1, 3-PS and PST. The high voltage lithium-ion battery electrolyte can obviously improve the cycle performance and the storage performance of a high voltage battery. In addition, the invention further discloses a high voltage lithium-ion battery.

Description

technical field [0001] The invention belongs to the field of lithium-ion batteries, and relates to an electrolyte that can obviously improve the cycle performance and high-temperature storage performance of a high-voltage lithium-ion battery, and a lithium-ion battery using the electrolyte. Background technique [0002] Lithium-ion batteries have the characteristics of high energy density, long life, wide operating temperature range, good safety, environmental protection, and low self-discharge rate. They have been widely used in mobile devices, digital products, energy storage power stations, power batteries and other fields. With the advancement of science and technology, the functions of digital products are becoming more and more powerful, and the insufficient battery life is becoming more and more obvious; at the same time, digital products have a tendency to become lighter and thinner. Insufficient battery performance has become a serious problem affecting the developm...

AI Technical Summary

Problems solved by technology

[0006] However, the experimental results show that nitrile solvents such as glutaronitrile and adiponitrile have poor compatibility with graphite negative electrodes of lithium-ion batteries, and polymerization reactions easily occur on the surface of the negative electrodes, preventing the deintercalation of lithium ions and causing deterioration of battery performance.

Most sulfones (such as methyl ethyl sulfone and sulfolane) are solid at room temperature, and can only be mixed with other solvents to form liquid electrolytes, with high viscosity and low conductivity; and there is also the problem of poor compatibility with graphite negative electrodes

At present, the development and use of new solvents such as nitriles and sulfone compounds used in the electrolyte of high-voltage lithium-ion batteries are relatively expensive, and the performance in practical applications also needs to be improved.

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