In-situ preparation of nanostructured α-MnO2/polypyrrole hybrid composite electrode materials for high performance supercapacitor

Abstract

In-situ manganese oxide/polypyrrole (MnO2/Ppy) nanocomposites have been prepared by a simple co-precipitation method using pyrrole and aqueous KMnO4 solution under ambient conditions. The effect of annealing temperature on the structure, morphology, specific surface area, and electrochemical capacitance properties have been studied. The as-prepared MnO2/Ppy nanocomposite has large BET surface area of 232 m2 g−1 with a pore size of 6.6 nm. The high discharge capacitance of as-prepared MnO2/Ppy nanocomposite is 290 F g−1, when the electrode is cycled in a aqueous solution of 0.1 M Ca(NO3)2·4H2O at a current density of 0.5 A g−1. The capacitance retention after 3,000 cycles is about 90% of the initial capacitance at a current density of 1 A g−1. A simple preparation method adopted to synthesize MnO2/Ppy nanocomposite is advantageous and the specific capacitance is high with good cycling stability.