Magnetite modified graphenenanosheets with improved rate performance and cyclic stability for Li ion battery anodes

Abstract

Magnetite modified graphene nanosheets (MGNSs) were synthesized through a simple ultrasonic method, electrochemical performances indicated that the obtained MGNSs exhibited remarkably high reversible lithium storage capacity (1235 mAh g⁻¹ after 50 cycles at 0.2 A g⁻¹), good rate capability (315 mAh g⁻¹ at 10 A g⁻¹) and improved cycling stability (450 mAh g⁻¹ after nearly 700 cycles at 5 A g⁻¹). The improved electrochemical performances of the obtained MGNSs could be attributed to its inherent electronic conductivity, excellent mechanical properties and expanded (002) interlayer spacing of GNSs. Furthermore, magnetite nanoparticles anchored onto graphene nanosheets (GNSs) could serve as spacers to reduce the stack/restack of GNSs during charge-discharge process and improve their electrochemical performances as anode materials for lithium-ion batteries (LIBs).