Galvanostatically deposited Fe: MnO2 electrodes for supercapacitor application

The present investigation describes the addition of iron (Fe) in order to improve the supercapacitive properties of MnO2 electrodes using galvanostatic mode. These amorphous worm like Fe: MnO2 electrodes are characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDAX), Fourier transform infrared spectroscopy (FTIR) and wettability test. The supercapacitive properties of MnO2 and Fe: MnO2 electrodes are investigated using cyclic voltammetry, chronopotentiometry and impedance techniques. It is seen that the supercapacitance increases with increase in Fe doping concentration and achieved a maximum of 173 F g−1 at 2 at% Fe doping. The maximum supercapacitance obtained is 218 F g−1 for 2 at% Fe: MnO2 electrode. This hydrous binary oxide exhibited ideal capacitive behavior with high reversibility and high pulse charge–discharge property between −0.1 and +0.9 V/SCE in 1 M Na2SO4 electrolyte indicating a promising electrode material for electrochemical supercapacitors.

► Simple and inexpensive method for synthesis of Fe: MnO2 thin films.
► Effect of different Fe concentrations on structural, morphological and wettability properties of MnO2.
► Applicable in supercapacitors with a maximum supercapacitance of 218 F g−1.
► Specific energy, specific power and coulomb efficiency of Fe: MnO2.