Influence of Ag Doping on the Electrochemical Supercapacitor Characteristics of Manganese Dioxide Prepared by Pulsed Potentiostatic Electrodeposition

Abstract

Manganese dioxide (MnO2) is a promising electrode material for electrochemical supercapacitor applications due to its low cost, eco-friendly and high theoretical specific capacitance in a wide potential window. In this study, MnO2 and Ag-doped MnO2 are prepared by cathodic electrodeposition on graphite substrate from electrolyte with the main compound of potassium permanganate using pulse potentiostatic technique. The effect of Ag doping on the morphology, structure and electrochemical properties of MnO2 materials are investigated. Scanning electron microscopy (FESEM), Energy Dispersive X-ray Spectroscopy (EDX), cyclic voltammetry (CV), galvanostatic charge-discharge measurement and electrochemical impedance spectroscopy (EIS) are used for characterization of the prepared materials. The results show that doping Ag into the MnO2 structure has improved electrochemical characteristics of materials. The specific capacitances are calculated for pure MnO2 and Ag-doped MnO2 to be 272.84 and 277.48 F/g, respectively. The prepared materials exhibit the high charge-discharge stability, maintaining at about 92 % for MnO2 and 95 % for Ag-doped MnO2 after 500 cycles of the charge-discharge operation.