Enhanced High-Temperature Cycle Life of LiFePO[sub 4]-Based Li-Ion Batteries by Vinylene Carbonate as Electrolyte Additive

Abstract
Addition of vinylene carbonate (VC) in electrolyte solution has been found to greatly improve the high-temperature cycling performance of -based Li-ion batteries. It has been established that the VC additive remarkably suppresses Fe dissolution from cathode and hence, subsequent Fe deposition on the anode side. Furthermore, the VC additive also significantly reduces formation of solid-electrolyte interface layers on both cathodes and mesocarbon microbead (MCMB) anodes. With VC addition, a 18650-type /MCMB cell has been shown to retain capacity after 980 cycles at under charge–discharge rates. This is in contrast with more than 25% capacity loss after merely 100 cycles when no VC is added.