Preparation, structural and electrochemical supercapacitive properties of sprayed manganese oxide film electrode

Manganese oxide (Mn3O4) thin films were deposited by spray pyrolysis technique at optimized temperature 400 degrees C. The hausmannite tetragonal crystal structure of Mn3O4 was confirmed by X-ray diffraction. The average grain size was found to be 70 nm for (301) prominent plane. Scanning electron micrographs revealed that material has high degree of porosity useful for supercapacitor application. The atomic force microscopy analysis showed that the surface morphology is rough. The electrochemical performance of Mn3O4 electrode tested using cyclic voltammetry at 0.25, 0.5 and 1 M molar of Na2SO4 electrolyte within the potential range of -1.6 to +1 V. Among the above molarities, 1 M Na2SO4 electrolyte showed high specific capacitance of 527 F g(-1) at low scan rate of 5 mV s(-1). The obtained specific energy, specific power and coulomb efficiency of Mn3O4 electrode were 6.52 Wh kg(-1), 4.5 kW kg(-1) and 89.94 %, respectively.