The Capacitive Performances of Porous Carbon Electrodes Investigated by Novel System for Electrochemical Testing of Supercapacitors

Simple and fast procedure for the preparation of supercapacitive platesis proposed. High  surface area activated carbons (above 2000 m2g-1), as active electrode materials, were obtained in two-stage process involving conventional carboni-zation of short and entangled hemp fibers acquired as waste from textile industry, and subsequent activation by potassium hydroxide. The capacitive properties of the plates prepared from carbons of different porous properties were investigated by cyclic voltammetry and electrochemical impedance spectroscopy. The characteriza-tion was performed in simply designed two electrode system as plates of a superca-pacitor which can provide standard electrochemical testing in the temperature range between 30 and 100° C and under the pressures of up to 3 bar. The highest capacitance values obtained at room temperature, using cyclic voltammetry, were 145 and 141 Fg-1.