A solid-state Li–air battery: computational studies of interfaces and relevance to discharge mechanism

There is much interest in developing new energy storage systems to replace currently available ones that mainly work based on Li-ion intercalations. One attractive area is the Li–air battery for which most of the research has involved liquid electrolytes. There have been few studies on the use of a solid electrolyte in a Li–air battery. Recently, we reported the successful use of a solid-state electrolyte in a Li–air battery resulting in a Li₂O product and potentially much higher energy density than in a Li–air battery based on either a Li₂O₂ or LiO₂ product (Science, 2023, 379, 499). In this paper we discuss how the discharge mechanism involved in this solid-state Li–air battery differs from that of a Li–air battery with a liquid electrolyte. The solid-state mechanism is further explored with density functional studies of various interfaces involving the discharge product. We discuss the relevance of the results to the discharge mechanism in the solid-state Li–air battery.