▎ 摘　　要

Freestanding nanoporous N-doped graphenewith encapsulated RuO2 nanoparticles is developed as a cathode for rechargeable Li-O-2 batteries. The stabilized metal oxide catalyst reduces charge overpotentials enabling high-efficiency rechargeable Li-O-2 batteries with a long cycling lifetime. This has important implications for the development of highly stable and catalytically active graphene-based cathodes for rechargeable Li-O-2 batteries.