High specific capacity of TiO2-graphene nanocomposite as an anode material for lithium-ion batteries in an enlarged potential window

TiO2-graphene nanocomposite was first synthesized by a facile gas/liquid interface reaction. The structure and morphology were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and Brunauer–Emmett–Teller measurements. The results indicate that TiO2 nanoparticles (ca. 10 nm in mean grain size) were successfully deposited onto the graphene sheets during the gas/liquid interfacial reaction process. The electrochemical performance was evaluated by using coin-type cells versus metallic lithium in an enlarged potential window of 0.01–3.0 V. A high specific charge capacity of 499 mAh g−1 was obtained at a current density of 100 mA g−1. More strikingly, the TiO2-graphene nanocomposite exhibits excellent rate capability, even at a high current density of 3000 mA g−1, the specific charge capacity was still as high as 150 mAh g−1. The high specific charge capacities can be attributed to the facts that graphene possesses high electronic conductivity, and the lithium storage performance of graphene is delivered during discharge/charge processes of TiO2-graphene nanocomposite between 0.01 and 3.0 V.

► TiO2-graphene composite was first synthesized by a gas/liquid interfacial method. ► The electrochemical performances were first evaluated between 0.01 and 3.0 V. ► The composite exhibits a high specific capacity and excellent rate performance.