Graphene-Wrapped ZnMn2O4 Nanoparticles with Enhanced Performance as Lithium-Ion Battery Anode Materials

ZnMn2O4 nanoparticles (NPs) wrapped by reduced graphene oxide (rGO) were fabricated via a two-step solvothermal method and used as an anode material for lithium-ion batteries (LIBs). Compared to pure ZnMn2O4, the ZnMn2O4 NPs/rGO composites deliver higher capacities of 1230 mAh g(-1) and 578 mAh g(-1) after 200 cycles at a current density of 100 mA g(-1) and 500 mA g(-1), respectively. The enhanced electrochemical performance of ZnMn2O4 NPs/rGO composites is mainly attributed to a distinctive structure (ZnMn2O4 NPs surrounded by flexible rGO), which can promote the diffusion of Li+, accelerate the transport of electrons and buffer volume expansion during the Li+ insertion/extraction process. Furthermore, the rGO sheets can effectively prevent the agglomeration of ZnMn2O4 NPs, thus, improving structural stability of the composites. The excellent electrochemical performance indicates that such ZnMn2O4 NPs/rGO composite structure has a great potential for high-performance LIBs.