Preparation of activated carbon from polyaniline by zinc chloride activation as supercapacitor electrodes

Activated carbon for supercapacitor electrode was prepared from polyaniline using chemical activation with ZnCl₂. The morphology, surface chemical composition, and surface area of the as-prepared carbon materials were investigated by scanning electron microscope, atomic force microscopy, X-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller measurement, respectively. Electrochemical characteristics were evaluated by cyclic voltammograms, galvanostatic charge/discharge, and electrochemical impedance spectroscopy tests in 6.0 mol L^?1 KOH aqueous solution. The electrochemical measurements showed that ZnCl₂ activation led to better capacitive performances. The activated carbon presented a high-specific gravimetric capacitance of 174 F?g^?1, with rectangular cyclic voltammetry curves at a scan rate of 2 mV s^?1, and it remained 93% even at a high scan rate of 50 mV s^?1. These demonstrated that activated carbon would be a promising electrode material for supercapacitors.