An Integrated Interfacial Design for High‐Energy, Safe Solid‐State Batteries

Solid‐state lithium metal batteries promise high‐energy density and enhanced safety but are hindered by interfacial instability and poor electrode–electrolyte contact. Now, Qiang Zhang and colleagues have developed a fluorinated polyether‐based polymer electrolyte that enables in situ formation of amorphous LiF‐rich interphases on both high‐voltage cathodes and lithium‐free and lithium anodes, enabling a potentially high specific energy density of 604 Wh kg −1 in a demo pouch cell with exceptional thermal safety.