High energy density titanium doped-vanadium oxide-vertically aligned CNT composite electrodes for supercapacitor applications

Abstract

In this study, we provide the first report on the supercapacitance behavior of titanium doped vanadium oxide films grown on vertically aligned carbon nanotubes using a chemical vapor deposition (CVD) technique. The capacitance of CVD derived titanium doped vanadium oxide–carbon nanotube composites was measured at different scan rates to evaluate the charge storage behavior. In addition, the electrochemical characteristics of the titanium doped vanadium oxide thin films synthesized by the CVD process were compared to substantiate the propitious effect of the carbon nanotubes on the capacitance of the doped vanadium oxide. Considering the overall materials loading with good rate capability and excellent charge retention up to 400 cycles, it can be noted that attractive capacitance values as high as 310 F g⁻¹ were reported. Ab initio theoretical studies, demonstrating the substantial improvement in the electronic conductivity of the vanadium oxide due to titanium doping and oxygen vacancies, have also been included corroborating the attractive experimental capacitance response.