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

Abstract In-situ manganese oxide/polypyrrole (MnO 2 /Ppy) nanocomposites have been prepared by a simple co-precipitation method using pyrrole and aqueous KMnO 4 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 MnO 2 /Ppy nanocomposite has large BET surface area of 232 m 2  g −1 with a pore size of 6.6 nm. The high discharge capacitance of as-prepared MnO 2 /Ppy nanocomposite is 290 F g −1 , when the electrode is cycled in a aqueous solution of 0.1 M Ca(NO 3 ) 2 ·4H 2 O 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 MnO 2 /Ppy nanocomposite is advantageous and the specific capacitance is high with good cycling stability.