Synthesis and Characterization of MnO[sub 2]-Based Mixed Oxides as Supercapacitors

Abstract
Mn/Pb and Mn/Ni mixed oxide were prepared at ambient temperature by reduction of KMnO4KMnO4 with Mn, Pb, and Ni salts. This low-temperature approach provides amorphous structure of the active material. The specific capacitance of pure MnO2MnO2 was estimated to be 166 F/g and increased to 210 and 185 F/g for Mn/Ni and Mn/Pb oxides, respectively. The carbon loading was optimized at 20 wt %. Based on a single electrode, the Mn/Ni mixed oxide showed a high rate capability of 3.12 Wh/kg at constant power discharge of 1 kW/kg. © 2003 The Electrochemical Society. All rights reserved.