Synthesis of Fire-Extinguishing High-Voltage Electrolytes for Safe Batteries

缺乏合适的替代溶剂阻碍了新功能电解质的进一步探索。本文中，我们设计并合成了用于LIB的氟化环状磷酸酯溶剂，2-（2，2，2-三氟乙氧基）-1，3，2-二氧磷杂环戊烷2-氧化物（TFEP）。由0.95 M LiN（SO 2F）2在TFEP/2，2，2-三氟乙基甲基碳酸酯中组成的电解质配方显示出优异的不燃性和零自熄时间，并使石墨阳极能够高度稳定地运行（约1000 ℃）。0.1 V vs锂）和高压LiNi0.5Mn1.5O4阴极（约4.7 V对锂），从而优于传统的电解质。这项工作开辟了电解质发展的新领域，使其朝着具有更高能量密度的安全LIB发展，最近被Nature Energy接受发表。

The lack of a suitable alternative solvent has hindered further exploration of new functional electrolytes. Herein we design and synthesize a fluorinated cyclic phosphate solvent, 2-(2,2,2-trifluoroethoxy)-1,3,2-dioxaphospholane 2-oxide (TFEP), for use in LIBs. An electrolyte formula composed of 0.95 M LiN(SO2F)2 in TFEP/2,2,2-trifluoroethyl methyl carbonate shows excellent non-flammability with zero self-extinguishing time and enables the highly stable operation of graphite anodes (ca. 0.1 V vs lithium) and high-voltage LiNi0.5Mn1.5O4 cathodes (ca. 4.7 V vs lithium), thereby outperforming the traditional electrolytes. This work opens new frontiers in electrolyte developments toward safe LIBs with higher energy densities, which was recently accepted for publication on Nature Energy.