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

摘要

Cathodic electrodeposition method has been developed for the fabrication of Ag-doped MnO_2 films from the KMnO_4 aqueous solutions containing AgNO_3 for the application in electrodes of electrochemical super-capacitors (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 MnO_2 films showed improved capacitive behaviour and lower electrical resistance compared to pure MnO_2 films. The highest specific capacitance (SC) of 770 F g~(-1) was obtained at a scan rate of 2 mV s~(-1) in the 0.5 M Na_2SO_4 electrolyte.