One-pot synthesis of ultrafine ZnFe2O4 nanocrystals anchored on graphene for high-performance Li and Li-ion batteries

A ZnFe2O4-nanocrystals/graphene-nanosheets (ZnFe2O4/G) nanohybrid has been prepared by a facile in situ hydrothermal route using Zn(NO3)(2)center dot 6H(2)O, Fe(NO3)(3)center dot 6H(2)O and graphite oxide (GO) as the precursors. Ultrafine ZnFe2O4 nanocrystals (below 10 nm) are confined by the few-layer graphene sheets reduced from GO, forming a unique sheet-like hybrid. In this structure, the direct restacking of the hydrophobic graphene sheets is refrained by loading ZnFe2O4 nanocrystals as the spacers and the aggregation of ZnFe2O4 nanocrystals is inhibited by the dispersing and confining effects of the graphene sheets. ZnFe2O4/G shows excellent rate capability and high-rate cycling stability for lithium storage. It also shows a high capacity when used as an anode for a ZnFe2O4/G-LiFePO4/C full cell.