以六水合硝酸镍为原料,尿素为沉淀剂采用微波水热法合成了Ni(OH)2.X射线衍射(XRD)证明材料为纯相α-Ni(OH)2,扫描电子显微镜(SEM)显示α-Ni(OH)2呈现直径约0.5~3.0μm的花球形貌,分散较均匀,沉淀剂的用量对花球的大小和团聚程度有影响.采用循环伏安以及恒电流充放电等技术对材料进行了电化学性能测试.结果表明,当尿素与六水合硝酸镍的摩尔比为3:1时所得到的α-Ni(OH)2具有最大的初始比电容,而尿素与六水合硝酸镍的摩尔比为2:1时所得到的α-Ni(OH)2具有更好的循环储能性能.
Ni(OH)2 particles were successfully prepared with Ni(NO3)2-6H20 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 a-phase. The SEM images revealed that the synthe- sized a-Ni(OH)2 particles were well dispersed and ball-flower like with diameters of 0.5-3 μm 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 mor- phologies and the electrochemical capacitance of the materials. When the molar ratio of the CO(NH2)2 to Ni(NO3)2-6H2O was 3:1, the obtained α-Ni(OH)2 had the maximal initial special capacity; when the molar ratio was 2:1, the α-Ni(OH)2 had the best cycle storage performance.