Preparation of Nickel and Manganese Oxides Composite via Co-Precipitation Method and its Supercapacitive Performance

Abstract

The nickel and manganese oxides (Ni-Mn oxides) were prepared by a simple co-precipitation process with sodium carbonate (Na2CO3) as precipitant. The products are the mixture of nickel oxides, manganese oxides and their solid solution. The phase and morphology of the synthesized product were characterized by X-ray diffraction and field emission scanning electron microscope. The electrochemical capacitive characterization was performed using cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) and electrical impedance spectroscopy (EIS) measurements in a 6mol/L KOH aqueous solution electrolyte. The result shows that a maximal specific capacitance value when stoichiometric amounts of NiCl2 and MnCl2 are equal (cationic ratio of Ni:Mn=1:1) which the specific capacitance is 110 F/g (at a current density of 1A/g). Overall we found that the nickel and manganese oxides have better electrochemical performance compared to the single parts, and while the introduction of nickel oxides can further improve the performance.