One-pot sonochemical synthesis of magnetite@reduced graphene oxide nanocomposite for high performance Li ion storage.

In this research, we introduce a one-pot sonochemical method for the fabrication of magnetite@reduced graphene oxide (Fe3O4@rGO) nanocomposite as anode material for Li-ion batteries. Fe3O4@rGO is synthesized under ultrasonic irradiations by using iron (II) salt and GO as raw materials. An in-situ oxidation-reduction occurs between GO and Fe2+ during the ultrasonic chemical reaction process. Fe3O4 particles with the size of ∼20 nm are uniformly deposited on the surface of rGO nanosheets. The electrochemical activity of Fe3O4@rGO is systematically evaluated as an anode material in Li-ion battery. Li-ion cells using Fe3O4@rGO as electrode deliver high discharge and charge capacities of 1433.6 and 907.8 mAh g-1 in the initial cycle at 200 mA g-1. Even performed at 500 and 5000 mA g-1, it is able to deliver reversible capacities of 846.4 and 355.6 mAh g-1, respectively, demonstrating outstanding Li-ion storage performance. This research presents a straightforward and efficient method for the fabrication of Fe3O4@rGO, which holds great potential in synthesis of other metal oxides on graphene sheets.