▎ 摘　　要

A novel litchi-like Fe3O4/graphene composite as a cathode material of lithium-air batteries was successfully synthesized by an effective solvothermal method, with cheap and eco-friendly iron salts. The litchi-like Fe3O4 nanoparticles (NPs) which could provide a larger electrochemical reaction surface were similar to 250 nm in size and homogeneously distributed onto the surface of conducting graphene sheets. Owing to synergistic effect between the litchi-like Fe3O4 nanoparticles and graphene sheets, Fe3O4/graphene composites (Fe3O4/GCs) exhibited much higher electrocatalytic activity compared to the Fe3O4 NPs. The charge/discharge tests showed that the lithium-air battery based on the litchi-like Fe3O4/graphene composite had an excellent discharge capacity of similar to 1638 mA h g(-1) at a voltage of 2.0-4.1 V at 50 mA g(-1), and also exhibited low charge potential and improved the energy efficiency as well as reversible capacity.