微乳法制备无定形NiO及其电化学电容行为

Preparation and Electrochemical Capacitance of Amorphous Nickel Oxide by Micro-emulsion

采用微乳法合成无定形Ni(OH)2前驱体,经煅烧得到NiO,通过TEM、XRD、TG、DSC对前驱体和产物的形貌、结构和性能进行表征。结果表明,NiO仍为无定形结构。在煅烧温度低于600℃时,晶体生长活化能为10.72kJ.mol-1,且晶体生长以界面扩散为主。采用恒流充放电、循环伏安和电化学阻抗方法研究了AC/NiO混合电容器的电容行为。结果表明,在100mA.g-1电流密度下,其比电容、比功率和比能量分别为104.4F.g-1、75W.kg-1和65.3Wh.kg-1,200次循环后容量保持率为87.7%。在0～1.5V电压范围内AC/NiO混合电容器具有良好的电容特性。

NiO was obtained by annealing amorphous Ni（OH）2 precursor that synthesized by micro-emulsion. The morphology, structure and performance of the precursor and product were characterized by TEM, XRD, TG and DSC. The results showed that the morphology of NiO was also amorphous. The activation energy for nanocrystallite growth was 10.72 kJ.mol^-1 below 600℃, indicated that NiO grew primarily by means of interfacial reaction. The capacitance performances of AC/NiO hybrid capacitor were researched by galvanostatic charge/discharge, cyclic voltammeter and electrochemical impedance spectroscopy. The results indicated that the specific capacitance, power and energy of AC/NiO hybrid capacitor were 104.4 F.g^-1, 75 W.kg^-1 and 65.3 Wh.kg^-1 at the current density of 100 mA.g^-1 respectively. The capacity retention was 87.7% after 200 cycles. AC/NiO hybrid capacitor exhibited excellent capacitance performance with the potential range from 0 to 1.5 V.