Preparation and Electrochemical Capacitance of α-Ni(OH)2 Synthesized by Microwave-assisted Hydrothermal Method

Ni(OH)(2) particles were successfully prepared with Ni(NO3)(2)center dot 6H(2)O as the raw material and CO(NH2)(2) as the precipitation agent by microwave-assisted hydrothermal method. The obtained Ni(OH)(2) were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and electrochemical measurements. XRD results showed that the as-prepared Ni(OH)(2) particles had the typical alpha-phase. The SEM images revealed that the synthesized alpha-Ni(OH)(2) particles were well dispersed and ball-flower like with diameters of 0.5-3 mu m which consisted of the aggregated flakes. Electrochemical properties were studied by cyclic voltammograms (CV) and galvanostatic charge-discharge tests in 6 mol/L KOH electrolyte. All the tests showed that the reactants ratio affected the morphologies and the electrochemical capacitance of the materials. When the molar ratio of the CO(NH2)(2) to Ni(NO3)(2)center dot 6H(2)O was 3:1, the obtained alpha-Ni(OH)(2) had the maximal initial special capacity; when the molar ratio was 2:1, the alpha-Ni(OH)(2) had the best cycle storage performance.