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

摘要

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. (C) 2012 Elsevier Ltd. All rights reserved.