Self-assembly of hybrid Fe2Mo3O8–reduced graphene oxide nanosheets with enhanced lithium storage properties

Abstract

Self-assembled Fe2Mo3O8–reduced graphene oxide (RGO) nanosheets are fabricated by a facile route, whereby crystalline Fe2Mo3O8 nanoparticles are grown on RGO nanosheets. The electrode made of the as-formed hybrid Fe2Mo3O8–RGO nanosheets exhibits a high specific capacity of 835 mA h g−1 after 40 discharge–charge cycles at 200 mA g−1. Even at a current density as high as 3000 mA g−1, the specific capacity reaches 574.8 mA h g−1, much larger than the theoretical capacity of graphite. The high lithium-reaction reversibility and durability of the hybrid Fe2Mo3O8–RGO nanosheets are investigated in detail. Based on in situ XRD analyses, a possible Li-cycling mechanism is proposed. Results show that the reversible conversion reaction involves the decomposition of Fe2Mo3O8 and the formation of metallic Mo, Fe and Li2O upon cycling. The presented synthetic strategy and the excellent lithium-storage performances make the unique hybrid Fe2Mo3O8–RGO nanosheets attractive as a promising anode candidate for next-generation high-performance lithium-ion batteries.