Optimized Electrolyte with High Electrochemical Stability and Oxygen Solubility for Lithium–Oxygen and Lithium–Air Batteries

Lithium–oxygen (Li–O2) batteries with high reversibility require a stable electrolyte against the side reactions with Li-metal anode and reactive oxygen species. Moreover, an electrolyte that can effectively utilize the low partial pressure of oxygen in the atmosphere has significant effect on the practical application of Li–air batteries. In this study, a localized high-concentration electrolyte (LHCE) was developed using 1H,1H,5H-octafluoropentyl 1,1,2,2-tetrafluoroethyl ether (OTE) as a diluent, which satisfies all these conditions simultaneously. The OTE-based LHCE exhibits much improved electrochemical performance in Li–O2 batteries and Li–air batteries in comparison to the conventional electrolyte and high-concentration electrolyte. The design principles of this electrolyte also provide important guidelines for research to further develop new electrolytes for Li–O2 and Li–air batteries.