Ultrafast lithium storage in TiO2-bronze nanowires/N-doped graphene nanocomposites

A TiO 2 -bronze/N-doped graphene nanocomposite (TiO 2 -B/NG) is prepared by a facile hydrothermal combined with hydrazine monohydrate vapor reduction method. The material exhibits macro- and meso-porosity with a high specific surface area of 163.4 m 2 g −1 . X-Ray photoelectron spectroscopy confirms the successful doping of nitrogen in the graphene sheets. In addition, the TiO 2 -B nanowires are substantially bonded to the NG sheets. Cyclic voltammetry and electrochemical impedance spectroscopy show that the N-doped graphene improves the electron and Li ion transport in the electrode which results in better electrochemical kinetics than that of the pristine TiO 2 -B nanowires. As a result, the charge transfer resistance of the TiO 2 -B/NG electrode is significantly reduced. In addition, the lithium diffusion coefficient of TiO 2 -B/NG increases by about five times with respect to that of pristine TiO 2 -B. The TiO 2 -B/NG composite exhibits a remarkably enhanced electrochemical performance compared to that of TiO 2 -B. It shows a discharge capacity of 220.7 mA h g −1 at the 10C rate with a capacity retention of 96% after 1000 cycles. In addition, it can deliver a discharge capacity of 101.6 mA h g −1 at an ultra high rate of 100C, indicating its great potential for use in high power lithium ion batteries. A TiO 2 -bronze/N-doped graphene nanocomposite was prepared by a facile method. The material exhibits outstanding rate capacity. A high reversible capacity of 101.6 mA h g −1 is obtained at the 100C rate, indicating its great potential for use in high power lithium ion batteries.