Improved storage capacity and rate capability of Fe 3O 4–graphene anodes for lithium-ion batteries

Abstract

By employing an ultrasonic deposition followed by heat treatment, magnetite (Fe 3O 4)–graphene nanosheet (GN) hybrid anode was synthesized to examine its electrochemical performance in Li-ion battery. The Fe 3O 4 nanocrystals with an average size of 10 nm can be homogeneously incorporated into the GNs to form Fe 3O 4–GN composites. In comparison with fresh GN anode, the composite anode exhibits high reversible capacity of 753 mAh/g at 0.1 C, high rate capability (533 mAh/g at 5 C), and enhanced cyclic performance with high coulombic efficiency. This improvement can be attributed to the fact that since Fe 3O 4 acts not only as a redox site but also as a spacer, the Fe 3O 4–GN hybrid creates a three-dimensional architecture that effectively facilitates ionic diffusion, Li-storage, and electronic transport. This result opens an efficient route for synthesis and application of GN hybrid as anode material for Li-ion batteries with superior performance.