Enhanced charge-discharge characteristics of RuO2 supercapacitors on heat-treated TiO2 nanorods

Abstract

Electrochemical capacitors based on RuO2 were prepared onto electrospun TiO2 nanorods. Further heat treatment of the TiO2 at 800°C under nitrogen was found to greatly improve the electrochemical performance of the RuO2 electrodes, especially at fast charge-discharge rates. The specific capacitance was found to decrease by only 33% when the scan rate increased from 10to1000mVs−1 (from 687to460Fg−1). The characteristic response time of the RuO2 electrode was found to be 0.15s when a heat-treated TiO2 substrate was used, which is 20 times better than that of the pristine TiO2 used.