Phase-dependent electrochemistry of TiO2 nanocrystals for supercapacitor applications

In the present work, we demonstrate the electrochemistry of nanocrystalline TiO2 in anatase (TiO2-A), anatase/rutile (TiO2-C) and rutile (TiO2-R) phases. Cyclic voltammetry (CV), galvanostatic charge-discharge, and electrochemical impedance spectroscopy were the techniques we employed to analyse the electrochemical properties of the electrodes. The observed results suggest that the electrode of TiO2-A possesses superior electrochemical properties due to its enhanced BET surface area, porous structure and low charge transfer resistance. At a low scan rate of 10 mV/s, CV analysis results imply a capacitance of 362 F/g for TiO2-A. Moreover, the galvanostatic charge -discharge study gives a specific capacitance of 312 F/g at a low scan rate of 10 A/g. Based on the higher energy density (882 W h kg(-1)) and power density (1260 kW kg(-1)), the TiO2-A electrode is a promising electrode material for fabricating supercapacitors. (C) 2016 Elsevier B.V. All rights reserved.