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

Abstract

The invention discloses high-voltage lithium-ion battery electrolyte and a lithium-ion battery using the high-voltage lithium-ion battery electrolyte. The lithium-ion battery electrolyte is prepared from a nonaqueous organic solvent, a lithium salt and an additive, and is characterized in that the nonaqueous organic solvent comprises a carbonic ester solvent and a carboxylic ester solvent which accounts for 5 to 50 percent of the mass of the electrolyte; the additive comprises a hydrofluoroether compound and at least one of sulfonic acid derivative from a cyclic disulfonic anhydrid, chain disulfonate, and cyclic disulfonate shown in a general formula I, a general formula II and a general formula III. The electrolyte is prepared by taking carboxylic ester of low viscosity and good wettability as one of the main solvents, and taking the sulfonic acid derivative of good film-forming property and the hydrofluoroether of good oxidative resistance as the functional additives, thus the formed lithium-ion battery electrolyte has the multiple advantages such as good electrode / electrolyte interface compatibility, strong oxidative resistance, high electric conductivity and wide liquid path range. The lithium-ion battery prepared by using the lithium-ion battery electrolyte is high in specific energy, less in gas yield of high-temperature storage, and long in cycle life.

Description

technical field [0001] The invention relates to the field of lithium ion batteries, in particular to a high-voltage lithium ion battery electrolyte and a lithium ion battery using the electrolyte. Background technique [0002] In recent years, with the multi-functionalization of electronic products such as mobile phones and tablet computers, consumers have higher and higher requirements for the energy density of lithium-ion batteries. [0003] At present, in order to increase the energy density of lithium-ion batteries, it is mainly through increasing the compaction density of active materials and selecting positive electrode active materials with higher charge cut-off potentials, such as: high-voltage lithium cobalt oxide, lithium nickel cobalt aluminum oxide, lithium nickel cobalt manganese oxide, lithium nickel manganese oxide, etc. However, increasing the charge cut-off potential of the positive electrode active material will increase its oxidation activity. When the li...

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Problems solved by technology

[0005] However, compared with carbonate solvents, carboxylate solvents are easy to reductively deposit on the surface of the negative electrode during the cycle, and the stability under high temperature conditions is also slightly insufficient.

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