Synthesis and Electrochemical Characterization of Vanadium Oxide on Carbon Nanotube Film Substrate for Pseudocapacitor Applications

An amorphous and hydrous vanadium oxide thin film of approximate thickness was electrochemically prepared onto a carbon nanotube (CNT) film substrate with a three-dimensional porous structure on a nanometer scale (denoted as a film electrode) for pseudocapacitor application. From cyclic voltammetry and galvanostatic discharging experiments in an organic electrolyte ( in propylene carbonate), the film electrode showed a specific Li-ion capacitance of at a potential scan rate of and a specific capacity of at a current density of , with respect to the mass of . Compared with prepared onto a Pt plate substrate (denoted as a thin-film electrode), the film electrode showed a threefold higher specific Li-ion capacitance. The improved specific Li-ion capacitance of in the film electrode is attributed to its electrode construction comprising a very thin film of on the conductive CNT film substrate with a three-dimensional nanoporous structure.