Recent advances in solid state lithium–oxygen batteries: Electrolytes and multi-functions

Lithium–oxygen batteries (LOBs) have drawn considerable attention in next generation energy storage systems owing to their large theoretical specific energy density. Unfortunately, the leakage of liquid electrolytes in LOBs generally causes major safety issues that hinder practical applications of LOBs. Therefore, it is significant to develop solid state electrolytes that can simultaneously avoid the electrolyte leakage and protect the lithium anode from air corrosion. In this work, we summarize recent developments in solid state LOBs and highlight their added values as flexible and water-proof power sources.