Corresponding Author

Yu-liang CAO(ylcao@whu.edu.cn)


Lithium-ion batteries (LIBs) have emerged as the most widely used energy storage devices owing to their high energy density and excellent cycling stability. However, safety issues have become a critical obstacle for the large-scale applications of LIBs in the energy storage systems and electric vehicles (EVs). Currently, LIBs use a low flash- and boiling-point organic carbonate as the electrolyte, which is extremely likely to cause firing or explosion. Although some flame-retardant additives can inhibit the combustion of electrolyte to a certain extent, it brings little effect in practical application. Therefore, the development of nonflammable electrolytes is an essential solution to eliminate the safety hazards of LIBs. The phosphorus-based electrolytes seem to be a good choice for flame-retardant or nonflammable electrolytes because of their low viscosity, high solubility, and low cost. In this paper, the problems and solutions of phosphate-based solvents as a safe electrolyte for LIBs are reviewed. Firstly, the feasibility and existing problems of phosphate ester as a solvent of electrolyte are introduced, and then the flame-retardant mechanism, flame-retardant or nonflammable phosphorus-based electrolytes are described by classifications, with emphasis on the electrochemical compatibility of such an electrolyte and its countermeasures. On this basis, we prospect the future research directions in high safety phosphorus-based electrolytes.

Graphical Abstract


lithium-ion battery, phosphorus-based solvent, electrolyte, safety, non-flammable solvent

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