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.