Fe2O3 nanocluster-decorated graphene as O2electrode for high energy Li–O2 batteries

Abstract

Fe₂O₃ nanocluster-decorated graphene (Fe₂O₃/graphene) hybrids with controlled contents of Fe₂O₃ were prepared by a facile electrochemical process. These Fe₂O₃/graphene hybrids were tested as O₂ electrodes for Li–O₂ batteries, which exhibited enhanced discharge capacities as compared to that of a pure graphene based O₂ electrode, e.g. the Fe₂O₃/graphene electrode with 29.0 wt% of Fe₂O₃ delivered a discharge capacity of 8290 mA h g⁻¹ and a round-trip efficiency of 65.9% as compared to 5100 mA h g⁻¹ and 57.5% for a pure graphene electrode. The excellent electrochemical properties of Fe₂O₃/graphene as an O₂ electrode is ascribed to the combination of the fast kinetics of electron transport provided by the graphene sheets and the high electrocatalytic activity for O₂ reduction provided by the Fe₂O₃.