有机磷酸酯阻燃电解液的研究进展

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.

Research Progress of High-Safety Phosphorus-Based Electrolyte

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.