Polyaniline-MnO2 composite electrode for high energy density electrochemical capacitor

Abstract

Nanostructured manganese dioxide (MnO2) was potentiodynamically deposited on polyaniline (PANI) matrix at a scan rate of 200 mV s-1. The composite electrode of PANI and MnO2 (PANI-MnO2) was characterized in 0.1 M Na2SO4 for electrochemical supercapacitors. Optimization of thickness of the PANI film and the amount of MnO2 deposition were necessary to realize large specific capacitance values. A specific capacitance of 715 F g-1 and an energy density of about 200 Wh kg-1 was obtained at a charge/discharge current density of 5 mA cm-2, based on the combined mass of PANI-MnO2. Long stability of the composite material was demonstrated. © 2004 The Electrochemical Society. All rights reserved.