Nitrogen and atomic Fe co-doped hollow carbon nanocages supporting RuPd nanoclusters as extraordinary high-performance nanoreactor-like cathode for lithium-oxygen batteries

Lithium-oxygen batteries (LOBs) have attracted considerable worldwide attention due to their exceptionally high theoretical energy density. Finding outstanding catalysts whereby Li2O2 can be directly and efficiently formed/decomposed is essential for achieving highly efficient LOBs. Herein, we report the design and preparation of an atomic Fe-dispersed hollow carbon nanocage supporting Ru-Pd binary nanoclusters. This catalyst exhibits extraordinarily high, top-ranking cathode performance towards the LOB. For our optimal sample, Ru0.8Pd0.2/Fe-CNCs, the specific capacity reaches 31,211 mAh g-1 with a very low charge overpotential of 0.64 V, and ultra-long cycle life of 300 cycles is realized. Systematic experimental and calculation results reveal the crucial role of the RuPd alloy nanoclusters in greatly improving OER activity and preventing the occurrence of side reactions. Meanwhile, the hollow nanocages, which have ultrathin mesoporous walls, act as "nanoreactors". The encouraging performance of our rationally designed cathode may provide a new pathway to develop advanced catalysts for LOBs.