A kind of electrolyte solution containing double boron imide lithium lithium salt against high voltage

Abstract

The invention provides high voltage resistant electrolyte solution with double boron imide lithium. The electrolyte solution comprises four compositions: organic solvent comprising double boron imide lithium, other lithium, carbonate ester and / or ether, other functional additive and high-voltage additive. The molar concentration of the lithium with double boron imide lithium and the high-voltage additive in the electrolyte solution is 0.001-2mol / L, the molar concentration of the other lithium in the electrolyte solution is 0-2mol / L, and the molar concentration of other functional additive in the electrolyte solution is 0-0.5mol / L. The lithium with double boron imide lithium is an ionic compound, and the positive ions are lithium ions. The electrolyte solution provided by the invention has double boron imide lithium and greatly improves the cryogenic property and the high voltage performance of the electrolyte solution. After the electrolyte solution is applied to a lithium battery at a high temperature of higher than 50 DEG C or a low temperature of lower than minus 20 DEG C, the percentage of the volume of the battery is improved, and the circulating life and the storing life of the lithium battery are prolonged.

Description

technical field [0001] The invention belongs to the technical field of chemical materials, and in particular relates to a high-voltage-resistant electrolyte solution containing lithium diboronimide lithium salt. Background technique [0002] At present, commercial lithium battery electrolytes are mainly composed of organic carbonates such as dimethyl carbonate (DMC for short), diethyl carbonate (DEC for short), ethylene carbonate (EC for short), etc., and lithium salts (mainly LiPF 6 )composition. The optimization and selection of organic carbonate non-aqueous electrolyte solutions is one of the important research directions to improve the comprehensive performance of lithium-ion batteries. The non-aqueous electrolyte solution used in lithium-ion batteries should generally meet the following requirements: (1) high ion conductivity, generally should reach 10-3S / cm; (2) high lithium ion migration number, in order to obtain high lithium ion Conductivity; (3) wide electrochemi...

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Problems solved by technology

However, although a large amount of fluorinated solvents solves the problem of electrolyte withstand voltage, the conductivity of the electrolyte is reduced, and the resistance of the SEI film is further increased, the charge and discharge performance is reduced, and the gas generation is very significant, and the battery expands greatly.

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