A highly stable lithium-ion power battery electrolyte

Abstract

The invention discloses a high-stability lithium ion battery electrolyte. The high-stability lithium ion battery electrolyte is prepared from, by mass, 14-18% of lithium hexafluorophosphate, 71-79% of a non-aqueous organic solvent, 3.5-6% of an electrolyte stabilizer and 3.5-5% of additives, wherein the non-aqueous organic solvent is at least one of carboxylic ester, halogenated carbonate, aromatic hydrocarbon and aryl halides, and halogen substitutes in the halogenated carbonate and the aryl halides are at least one of F, Cl and Br; the electrolyte stabilizer is formed by combination of hexamethyl disilazane, ethanol amine and triphenyl phosphate in a mole ratio of 1:(0.5-0.68):(0.25-0.35); the additives are at least one of maleic anhydride, methylene methanedisulfonate, ammonium acetate, fluorocarbonate, fluoroether and phosphazene and derivatives thereof. The high-stability lithium ion battery electrolyte is stable in chromaticity, and prepared batteries are excellent in cycle performance.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to a highly stable electrolyte solution for lithium ion power batteries. Background technique [0002] Lithium-ion batteries are widely used in 3C digital products, electric vehicles, military aerospace and other fields due to their high working voltage, high energy density, long cycle life, and environmental friendliness. With the improvement of people's living standards, higher requirements are put forward for the working environment, energy density, and fast charging and discharging of lithium-ion batteries. [0003] As an important part of lithium-ion batteries, the electrolyte plays a role in transporting charges between the positive and negative electrodes of the battery, and is crucial to the capacity performance, cycle performance and high and low temperature performance of the battery. Lithium hexafluorophosphate is currently the only lithium salt used commer...

AI Technical Summary

Problems solved by technology

However, lithium hexafluorophosphate has poor thermal stability and is easily decomposed into lithium fluoride and phosphorus pentafluoride. Due to the active chemical properties of phosphorus pentafluoride, it can react with trace proton impurities in the electrolyte, thereby causing electrolyte acidity And the rapid rise of chroma will deteriorate the quality of electrolyte, reduce the performance of battery capacity and cycle performance

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