Silicon-contained lithium ion battery electrolyte and silicon-contained lithium ion battery

Abstract

The invention discloses a silicon-contained lithium ion battery electrolyte which comprises an organic solvent, a conductive lithium salt and an additive. The additive comprises at least one type of fluorocarbonate compound, at least one type of acid anhydrides compound and at least one type of nitrile compound. The silicon-contained lithium ion battery electrolyte belonging to the technical fieldof lithium ion batteries has the advantages that the fluorocarbonate compound is added to inhibit decomposition of the electrolyte, the acid anhydrides compound can effectively avoid silicon expansion from causing fracture of an interfacial film, and the nitrile compound can reduce silicon expansion. Due to cooperation of the compounds, the battery has superhigh circulation stability and excellent high temperature storage performance.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a silicon-containing lithium ion battery electrolyte and a silicon-containing lithium ion battery. Background technique [0002] With the advent of the information age, the demand for energy storage is increasing. Based on its excellent performance, lithium-ion batteries are widely used in the field of energy storage, such as electronic devices such as smart phones, tablet computers, and Bluetooth headsets. However, its battery life in electronic equipment still cannot meet people's needs. In order to develop lithium-ion batteries with long battery life, it is of great advantage to use high-capacity anode materials. Silicon has attracted the attention of researchers because of its high gram capacity, which can reach 4200mAh / g. However, its expansion rate reaches 400%, which restricts the commercial application of silicon. [0003] At present, there a...

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Problems solved by technology

[0004] The purpose of the present invention is to solve the problem of short cycle life and high temperature gas production of silicon-containing lithium-ion batteries, and provide a silicon-containing lithium-ion battery electrolyte and a silicon-containing lithium-ion battery. A high-strength interfacial film is formed on the negative electrode to alleviate the volume expansion of silicon and inhibit the decomposition of the electrolyte, making the battery have ultra-high cycle stability and excellent high-temperature storage performance

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