Polypyrrole-Covered MnO₂ as Electrode Material for Hydrid Supercapacitor

Abstract

MnO 2 has been studied as hybrid electrode material in aqueous asymmetric supercapacitor. It possesses the advantages of low cost, sufficiently high specific capacitance, and environmentally friendly nature. We studied the blend formed by electrochemical polymerization of pyrrole monomer (Py) deposited onto MnO 2 particles. The composite material (PPy/MnO 2 ) has been characterized by different methods including cyclic voltammetry, chronoamperometry, X-ray diffractometry and BET measurements. At a constant current density 2 mA cm −2 the specific capacitance was calculated from galvanostatic charge-discharge cycling tests. It has been demonstrated that the asymmetric supercapacitor using (PPy/MnO 2 ) composite material has high specific capacitance of 141.6 F g −1 compared with 73.7 F g −1 for MnO 2 .