Lithium ion battery electrolyte, preparation method and lithium ion battery

Abstract

The invention provides a lithium ion battery electrolyte, a preparation method thereof and a lithium ion battery. The lithium ion battery electrolyte comprises a solvent, an electrolyte lithium salt and an additive, the electrolyte lithium salt and the additive are dispersed in the solvent, and the additive is pentafluorophenyltriethoxysilane. The pentafluorophenyltriethoxysilane is used as an additive, so that the pentafluorophenyltriethoxysilane can be oxidized earlier than other materials of the electrolyte, and an oxidation product can form a more stable film with lower internal resistanceon an interface so as to inhibit decomposition of the electrolyte; meanwhile, pentafluorophenyltriethoxysilane can effectively adsorb byproducts hydrogen fluoride and hydrogen ions and fluorine ionsformed by ionization of the byproducts hydrogen fluoride, stripping of active substances caused by corrosion of the byproducts is prevented, and the long-cycle stability of the battery is guaranteed.

Description

technical field [0001] The invention relates to the technical field of batteries, in particular to a lithium-ion battery electrolyte, a preparation method, and a lithium-ion battery. Background technique [0002] Lithium-ion batteries have the advantages of high output voltage and long cycle life, and thus occupy a dominant position in the current commercial secondary batteries. Moreover, lithium-ion batteries have a variety of alternative cathode or anode materials, which provides room for performance modification. For example, it is a proven and effective means to use a cathode material with a higher operating voltage (>3.7V) in order to increase the energy density. [0003] However, for lithium-ion batteries operating at higher voltages, the organic carbonate-based electrode solution used in traditional technologies will undergo severe oxidation and decomposition, making it difficult to exist stably, and will also produce hydrogen fluoride (hydrogen fluoride), a by-pr...

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Problems solved by technology

[0003] However, for lithium-ion batteries operating at higher voltages, the organic carbonate-based electrode solution used in traditional technologies will undergo severe oxidation and decomposition, making it difficult to exist stably, and will also produce hydrogen fluoride (hydrogen fluoride), a by-product that seriously affects the electrode material and electrode interface. HF)

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