A self-cooling and flame-retardant electrolyte for safer lithium ion batteries

Abstract

The rational design of flame-retardant electrolytes is essential for improving the safety of lithium ion batteries. Cooling is the key to curbing thermal runaway and compatibility is the basis to ensure electrochemical performance. Here we design a composite electrolyte with a double safety protection mechanism with self-cooling and flame-retardant effects simultaneously. N,N-Dimethylacetamide (DMAC) as a Lewis base can improve the thermal stability and perfluoro-2-methyl-3-pentanone (PFMP) with a self-cooling function can act as an internal micro-fire-extinguisher. Acceptable electrochemical performance is ensured via the introduction of a fluorocarbon surfactant (FS) that can improve the interface compatibility. This composite electrolyte is a good alternative for lithium ion batteries as it presents beneficial properties both in electrochemical performance and thermal stability.