有机磷酸酯阻燃电解液的研究进展

Research Progress of High-Safety Phosphorus-Based Electrolyte

随着锂离子电池的市场拓展,安全性问题已成为电动汽车、大规模储能等应用领域关注的首要问题.目前商品化的锂离子电池普遍采用低沸点碳酸酯类电解液,其易燃性成为电池不安全性的主要隐患.为了提高锂离子电池的本征安全性,阻燃或不燃性电解液成为近年来研究的热点,其中以磷酸酯为溶剂的阻燃型或不燃型电解液受到广泛关注.本文主要介绍磷酸酯阻燃和不燃电解液的研究状况,分析了这类电解液与锂离子电池正负极的兼容性问题,讨论了改善磷酸酯电解液电化学兼容性的途径,提出了发展高效、安全、稳定的不燃电解液的一些思路.

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.