Physicochemical and Electrochemical Properties of Glyme-LiN(SO2F)2 Complex for Safe Lithium-ion Secondary Battery Electrolyte

Abstract

Electrolyte performance of CH3-(OC2H4)3-CH3 (TG)/LiN(SO2F)2 (LiFSI) 1:1 molar mixture was investigated for high-safety lithium-ion secondary batteries by various physicochemical and electrochemical measurements. The TG-LiFSI electrolyte formed 1:1 complex, and showed relatively high thermal stability. Stable charge/discharge (intercalation/deintercalation) of lithium ions with both LiFePO4 positive electrode and graphite negative electrode were enabled with high coulombic efficiency and long cycles. Moreover, long cycle charge/discharge operations of [LiFePO4 positive electrode|TG-LiFSI electrolyte|graphite negative electrode] cell was achieved with 82% of capacity retention at 100 cycles.