Preparation and electrochemical capacitance behavior of TiO 2-B nanotubes for hybrid supercapacitor

Abstract

TiO 2-B nanotubes were fabricated by a simple mixed solvothermal reaction and subsequent heat treatment at 400 °C. It was found that the prepared TiO 2-B nanotubes are composed of polycrystalline phase with inner diameter of about 8 nm, outer diameter of about 10 nm and length of about several hundreds of nanometers. The hybrid supercapacitor using TiO 2-B nanotubes as the negative electrode and multiwalled carbon nanotubes (MWCNTs) as the positive electrode was assembled. The cells delivers an energy density of 19.3 Wh/kg at a rate of 10 C which is compatible with a fast charging/discharging device, intermediate between electrochemical double layer capacitor and Li-ion batteries.