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

Abstract

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.