Electrolyte for lithium ion battery

Abstract

The invention discloses an electrolyte for a lithium ion battery. The electrolyte comprises lithium salt, carbonic ester compounds, an ionic liquid and additives. By selecting a solute and a solvent of the electrolyte and optimizing the ratio of the components of the electrolyte and the addition mode of the ionic liquid and additives and through self-controlled adjustment of parameters of the electrolyte system such as viscosity, freezing point, boiling point, heat stability, chemical stability and the like changing slightly with the change of the electrolyte operating environment, the electrolyte's wettability and compatibility with the positive pole piece and negative pole piece of a lithium titanate lithium ion battery and a diaphragm can be effectively enhanced. In addition, through the synergism between the ionic liquid in the electrolyte and the additives, stability and functionality of the electrolyte can be effectively raised. Thus, high-rate performance of the lithium titanate lithium ion battery is improved, and the problem of battery swelling after multiple circulations is solved.

Description

technical field [0001] The invention relates to the technical field of lithium ion batteries, in particular to an electrolyte solution for lithium ion batteries. Background technique [0002] Lithium-ion batteries have the advantages of high working voltage, no memory effect, low self-discharge rate, long cycle life, and high energy density. They are used in portable electronic devices, new energy vehicles, energy storage, and starting power supplies. While applying lithium-ion batteries in related fields, the requirements for lithium-ion batteries in terms of energy density, cycle performance, safety performance and stability have also increased. Lithium-ion batteries are mainly composed of positive pole pieces and negative pole pieces. , Diaphragm, electrolyte and shell, among which, the electrolyte is usually composed of lithium salt and organic solvent, the electrolyte is an important part of the lithium-ion battery, and its performance has a direct impact on the improve...

AI Technical Summary

Problems solved by technology

[0005] The invention provides an electrolyte solution for a lithium ion battery to solve the problem that the parameters of the electrolyte solution such as viscosity, freezing point, boiling point, thermal stability, and chemical stability cannot be automatically adjusted with changes in the environment, resulting in the electrolyte being inconsistent with the positive electrode. The wettability and compatibility between the pole piece and the negative electrode piece are poor, and the electrolyte and the negative electrode material cannot form an effective and high-quality SEI film in a short time, which leads to the electrolyte on the positive pole piece and the negative pole piece. Long penetration time; at the same time, due to the low functionality and stability of the electrolyte, the high-rate performance of the lithium titanate lithium-ion battery is low, and after many cycles, the battery has a serious problem of flatulence

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