High-pressure electrolyte for high-nickel ternary cathode material system lithium ion battery

Abstract

The invention discloses a high-pressure electrolyte for a high-nickel ternary cathode material system lithium ion battery. The high-pressure electrolyte is composed of an organic solvent, an electrolyte lithium salt, a cathode film-forming additive, an anode film-forming additive and an anti-oxidation additive; the cathode film-forming additive is 1,5,2,4-dioxadithiane 2,2,4,4-tetraoxide, the anode film-forming additive is 4-fluoro-1,3-dioxolan-2-one, the anti-oxidation additive is tris[2-[2-(2-methoxyethoxy)ethoxy]ethyl]orthoborate, and by taking the total mass of the high-pressure electrolyte as a reference, the addition amount of the athode film-forming additive is 0.5-1%, the addition amount of the anode film-forming additive is 2-5%, and the addition amount of the anti-oxidation additive is 0.5-1%. The high-pressure electrolyte has relatively good oxidation resistance, high temperature resistance and safety characteristics, guarantees the battery to have relatively good cycle life, also has relatively high electrical conductivity, is capable of guaranteeing the high rate and power characteristics of the battery, also has relatively high safety, and is capable of substantially improving the safety performance of the power battery.

Description

technical field [0001] The invention relates to the technical field of lithium-ion battery preparation, in particular to a high-voltage electrolyte solution for a lithium-ion battery with a high-nickel ternary positive electrode material system. [0002] Background technique [0003] In recent years, high energy density lithium-ion batteries have received more and more attention. Although the charging voltage of lithium-ion batteries of the three systems of lithium cobalt oxide, ternary material, and lithium manganate has reached 4.5V, their energy The density still cannot meet the needs of electric vehicles and other high energy density electronic products. Among them, the ternary material (nickel-cobalt-lithium manganate) can greatly increase the specific capacity of the material by increasing the nickel content, so the high-nickel ternary material must be an ideal material for large batteries in the future. [0004] However, the charging voltage of high-nickel ternary m...

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Problems solved by technology

[0007] The present invention aims to solve the problem that the high-voltage electrolyte in the prior art easily causes the metal ions in the positive electrode material to dissolve under high temperature and high pressure, resulting in an increase in impedance, a rapid decline in the cycle performance of the battery, and poor safety performance. A high-voltage electrolyte solution for a high-nickel ternary positive electrode material system lit

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