《Research Progress on Novel Fluorides in Lithium-ion Battery Electrolytes》

With the rapid development of portable electronic devices and electric vehicles, there is an urgent need for lithium-ion batteries with high energy density and safety. The development of electrolytes with wide electrochemical windows and non-flammable is essential to achieve high energy density and safety for lithium-ion batteries. However, the development of conventional carbonate electrolytes is limited by the narrow electrochemical window and flammability. The introduction of fluorine-containing compounds into the electrolyte can improve the film-forming, oxidation stability and combustibility of the electrolyte, and effectively improve the comprehensive performance of the battery. In this paper, the research progress of new fluorides in lithium-ion battery electrolytes is reviewed from the aspects of lithium salts and solvents, firstly, the characteristics of three new fluorine-containing lithium salts in terms of thermal stability, electrochemical stability, film-forming properties and passivation ability of aluminum current collectors are introduced, and secondly, the physical and chemical properties of solvents such as carbonates, carboxylic esters, ethers, and aromatic hydrocarbons before and after fluorine substitution, as well as their effects on ionic conductivity, interface formation ability, oxidation resistance, wide temperature performance and flammability of electrolytes are compared. The application of some new fluorocarbonates, fluoroethers and fluoroaromatic hydrocarbon solvents in lithium-ion battery electrolytes is highlighted, and finally the scientific challenges and limitations in the development and application of fluorides are summarized, and the future development direction of fluorides in lithium-ion battery electrolytes is prospected.

https://esst.cip.com.cn/CN/10.19799/j.cnki.2095-4239.2023.0401