Electrolyte and application thereof

Abstract

The invention provides an electrolyte and application thereof. The electrolyte comprises a lithium salt, a solvent, an additive A and an additive B, the invention also relates to application of the electrolyte. The electrolyte provided by the invention is a phosphate hexaester electrolyte capable of improving the normal-temperature cycle and low-temperature performance of the battery; according to the electrolyte, a phosphate additive and other film-forming additives are used, a compact protective film can be formed on the surface of an electrode, the performance of a battery under a high-voltage system can be achieved, and the cycle performance of the battery is improved. The electrolyte contains fluorine, sulfonyl and other groups with high electron delocalization, dissociation of lithium salt in a low-temperature environment is facilitated, and the low-temperature performance of the battery can be improved.

Description

technical field [0001] The invention belongs to the field of lithium batteries; in particular, it relates to an electrolyte and an application thereof. Background technique [0002] With the progress and development of science and technology, chemical power supply technology is becoming more and more mature. As a kind of chemical power source, lithium battery has the advantages of high energy density, good cycle performance, long life, no memory effect, clean and environmental protection, etc., so it is widely used in all aspects of people's life. [0003] In recent years, the research on power batteries has been intensified all over the world and has been widely deployed around the world. However, with the expansion of application fields, people's performance requirements for lithium batteries are becoming more and more stringent. Lithium batteries are composed of positive and negative active materials, conductive agents, current collectors, separators, and electrolytes. ...

AI Technical Summary

Problems solved by technology

[0004] Lithium hexafluorophosphate and carbonate in the conventional electrolyte system can no longer meet the requirements of high-voltage systems such as lithium manganate and high-nickel ternary

At a higher voltage, lithium hexafluorophosphate and carbonate electrolytes in the conventional electrolyte system are prone to side reactions, which affect the cycle performance of the battery; at the same time, it also affects the cycle life of the battery, etc.

In addition, due to the poor low-temperature performance of conventional lithium hexafluorophosphate and carbonate electrolytes, the solvent’s ability to dissociate lithium salts at low temperatures decreases, resulting in a decrease in the conductivity of the electrolyte.

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