A magnetite nanocrystal/graphene composite as high performance anode for lithium-ion batteries

A facile single step solvothermal route has been developed to prepare a composite of Fe ₃O ₄ nanoparticles and graphene nanosheets. The synthetic protocol takes advantage of the ethylene glycol assisted partial reduction of Fe ³⁺ species to form Fe ₃O ₄, the reduction of graphene oxide into graphene, and the preferential attachment of fine Fe ₃O ₄ nanoparticles onto graphene sheets in one step. No additional reductive agent or calcination step is needed, which favors an effective, operationally simple and low-cost preparation process. The cycling properties of Fe ₃O ₄/graphene nanocomposite have been evaluated by galvanostatic charge-discharge measurements. The effect of graphene additive ratios on electrochemical performance has been investigated. The results show that the nanocomposite with a moderate graphene content of 18.5 wt% integrates high reversible capacity and good cyclic stability, delivering a capacity of 750 mAh/g after 40 cycles at 50 mA/g.