Performance of Candlenut Shell (Alleuretus moluccana) Based Supercapacitor Electrode with Acid Electrolytes and Their Salts

Abstract

Candlenut shell was used as the precursor for activated carbon-based electrodes which prepared through two stages, namely carbonization and activation. The surface of the activated carbon was modified with HNO3. Characterization of carbons and activated carbon was performed by SEM, BET, FT-IR test and capacitance analysis using Cyclic Voltammetry. The result of SEM analysis shows that carbon pore formation has occurred after activation with H3PO4. The surface area of carbon and activated carbon determined by the BET method is 125,828 m2/g and 142,435 m2/g, respectively. The results of FTIR and Boehm titration analysis showed an increase in oxygen-containing functional groups after modification with HNO3. Based on the results of the analysis using Cyclic Voltammetry obtained the highest specific capacitance of unmodified activated carbon is 145.49 mF/g in H2SO4 0.5M electrolyte. In addition, the highest specific capacitance of activated carbon modified with HNO3 is 155.92 mF/g obtained in HCl 0.1 M electrolyte. In the same condition, the contribution of salt electrolyte (Na2SO4 0.5 M and 0.1 M) in the specific capacitance of candlenut shell based supercapacitor electrodes is a little bit lower compared to the acid electrolytes.