A kind of electrolyte solution for lithium ion battery and lithium ion battery

Abstract

The invention provides an electrolyte solution for a lithium-ion battery and a lithium-ion battery. The first additive silazaborane compound is added. The additive can undergo an oxidation reaction on the surface of the positive electrode to form a CEI film. On the one hand, the CEI film can effectively isolate the electrolytic On the other hand, the CEI film generated by the present invention is stable, which can ensure that the positive electrode material is not damaged, and at the same time ensure that the electrolyte is not oxidized and decomposed under high voltage, thereby improving the performance of lithium-ion batteries under high voltage. lifespan. Among them, the silicon atoms and boron atoms in the first additive can also increase the migration rate of active lithium ions, thereby reducing the interfacial impedance. At the same time, the silicon atoms and boron atoms can also serve as anion acceptors, which can capture the lithium ion produced by lithium salts and other additives. Hydrofluoric acid prevents hydrofluoric acid from attacking the CEI film on the surface of the positive electrode material, thereby ensuring the stability of the CEI film, achieving the purpose of increasing capacity retention and improving high-temperature cycle and low-impedance performance.

Description

technical field [0001] The invention relates to the field of lithium batteries, in particular to an electrolyte solution for a lithium ion battery and a lithium ion battery. Background technique [0002] Lithium-ion batteries are widely used in 3C digital, new energy vehicles, energy storage base stations and aerospace fields because of their low raw material cost, good safety performance, high working voltage, large specific energy, and long cycle life. [0003] Electrolyte, as the "blood" of lithium-ion batteries, is one of the important components of lithium-ion batteries. It is responsible for the transmission of lithium ions between the positive and negative electrodes. etc. play a vital role. However, the current commercial carbonate-based solvents are prone to side reactions between the electrolyte and the surface of the positive electrode material under high-voltage and high-temperature environments, which continuously consume active lithium ions, resulting in the d...

AI Technical Summary

Problems solved by technology

[0005] One of the objectives of the present invention is to provide an electrolyte solution for lithium ion batteries, which solves the problem that the current lithium ion battery electrolyte is prone to side reactions with positive electrode materials, and the electrolyte solution of the present invention effectively isolates the electrolyte solution from positive electrode materials. side reactions, thereby effectively improving the storage and cycle performance of lithium-ion batteries under high temperature and high pressure

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