Influence of nitric acid treatment of carbon on capacitance performance of an all solid state supercapacitor

The influence of carbon properties on the capacitance performance of a supercapacitor based on carbon electrodes and solid polymer electrolyte is presented in this work. Three carbons of different surface area have been investigated. The carbons have been used in supercapacitors as received and after chemical treatment with nitric acid. The chemical treatment provides to modify the surface properties of carbons. The surface area of treated carbons modifies in different way in dependence of type of used carbon. However, independently by surface area of carbons, better capacitance performances have been obtained by supercapacitors using modified carbons. This is likely due at higher utilization of surface area of carbon caused by an increased hydrophilicity and consequently by a improved electrode/electrolyte interface. Decay in capacitance performance was evidenced during cycling test carried out in cyclic voltammetry mode on supercapacitor with treated carbon.