Electrochemical properties of carbon-coated TiO2 nanotubes as a lithium battery anode material

To use as an anode material of lithium batteries, carbon-coated TiO2 nanotubes are prepared by hydrothermal reaction of rutile particles, subsequent sol–gel mixing with poly(vinyl pyrrolidone), and heat treatment at 300–500 °C. The carbon-coated TiO2 nanotubes are also characterized by morphology observation, crystalline property analysis, potentiostatic redox behaviors, and galvanostatic discharge–charge evaluations at low and high rates. When annealed at 300 °C, the amorphous phase of carbon layers which are covered on the TiO2 nanotubes dominates the anatase TiO2 nanocrystalline phase. When annealed at 500 °C, the carbon-coated TiO2 nanotubes exhibit superior cyclic performance and high-rate capability, due to the crystalline phase in the carbon-coated layer formed by annealing at high temperature. ► Carbon-coated TiO2 nanotubes are prepared by sol–gel mixing with poly(vinyl pyrrolidone). ► The poly(vinyl pyrrolidone) component forms partially crystalline carbon layer. ► The carbon layer allows an excellent cycle performance and high-rate capability for lithium-ion batteries.