Cathodic electrodeposition of Ag-doped manganese dioxide films for electrodes of electrochemical supercapacitors

Cathodic electrodeposition method has been developed for the fabrication of Ag-doped MnO2 films from the KMnO4 aqueous solutions containing AgNO3 for the application in electrodes of electrochemical supercapacitors (ES). The films were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), cyclic voltammetry (CV) and impedance spectroscopy. The Ag-doped MnO2 films showed improved capacitive behaviour and lower electrical resistance compared to pure MnO2 films. The highest specific capacitance (SC) of 770Fg−1 was obtained at a scan rate of 2mVs−1 in the 0.5M Na2SO4 electrolyte.