화학공학소재연구정보센터
Electrochimica Acta, Vol.138, 1-8, 2014
High performance super-capacitive behaviour of deposited manganese oxide/nickel oxide binary electrode system
The chrono-potentiometry technique was used to deposit MnO2-NiO binary metal oxide film on a stainless steel substrate at room temperature. During the electrodeposition process, the concentration of nickel acetate is varied in the fixed 0.01 M manganese acetate solution. The products were characterised by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX) and field emission scanning electron microscopy (FESEM). Their capacitive behaviour was studied by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy in two different alkaline electrolytes using a three electrode set-up. The MnO2-NiO binary metal oxide electrode deposited from Ni(CH3COO)(2)center dot 4H(2)O:Mn(CH3COO)(2)center dot 4H(2)O at a molar ratio of 0.25:0.01 (molar:molar) was found to be the best electrode with the lowest transfer resistance based on the Nyquist plots. The specific capacitance of the best electrode, NiO-25, exhibited a specific capacitance of 435 Fg(-1) and 681 Fg(-1) with an energy density of 242 Whkg(-1) and 213 Whkg(-1) in 0.5 M Na2SO4 and 0.5 M KOH electrolyte, respectively. (C) 2014 Elsevier Ltd. All rights reserved.