High performance supercapacitor applications of activated carbons derived from biomass

Nowadays, increasing energy demand, rapid depletion of fossil fuels and environmental problems have led the society to find new energy production ways and to store the produced energy efficiently. Supercapacitors, as promising energy storage devices, which are of great interest in the field of energy storage improvement, have interesting features such as fast charge/discharge capability, high power density and long cycle life. Carbon-based materials are of great interest in supercapacitor applications due to their properties such as high porosity and surface area, good electrical conductivity. In this study, activated carbons were produced from pomegranate marcs to be used as electrode material in supercapacitors. The electrochemical performances of the produced activated carbons with different surface properties were investigated. Production was carried out by chemical activation method with KOH and ZnCl2 activation tools at different impregnate rates and temperatures. The structural and morphological properties of the produced activated carbons were investigated using N2 adsorption-desorption isotherm (BET surface analysis), scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The electrochemical properties of electrodes were perfomed using cyclic voltammetry (CV), galvanostatic charge discharge (GCD) and electrochemical impedance spectroscopy (EIS) methods. As a result of the analyses, the produced activated carbon at 500 °C at a ratio of 1:1 (ZnCl2/Pomegranate pulp, w/w) showed the highest surface area with 1384 m2/g. The electrochemical test results show that an excellent specific capacitance value of 201 Fg-1 at 0.1 A/g in 6 M KOH electrolyte was achieved by using Super P Carbon black as a conductivity enhancer, with electrode material with high microporous area. In conclusion, the results confirm that pomegranate-based carbon has the potential to be a promising electrode material for supercapacitors.