CaTiO3 perovskite in the framework of activated carbon and its effect on enhanced electrochemical capacitance

Abstract

Modifications of activated carbon materials (ACs) towards an increase in the electronic and ionic conductivities are expected to improve their capacitance in the absence of a conductive agent. Char derived from cotton straw feed were heat-treated at 800 °C in the presence of TiO2. Simultaneously KOH and K2CO3 were used as activation agents. That process resulted in the formation of perovskite CaTiO3 with an involvement of calcium present in carbon as an impurity. The composite were extensively characterized from the point of view of a texture, surface chemistry and electrochemical performance. The results indicated that perovskite with impurities affected the ionic conductivity and enhanced the capacitive performance of ACs. The capacitance measured on the electrode made of the best performing sample in both three- and two-electrode cell systems in the absence of a conductive agent - carbon black was 270 F g−1 and 185 F g−1 at current density of 0.5 A g−1, respectively. The results suggest that the AC/perovskite composites are promising electrodes of the high-performance supercapacitors.