碱性全固态纳米晶NiO电容器的电化学电容特性

Electrochemical Capacitance of Alkaline All-solid-state Supercapacitor Based on Nanocrystalline NiO

在乙醇-水体系中制备了N i(OH)2前驱体,300℃下对其进行热处理制得N iO纳米晶。溶剂浇铸法制备了PVA-KOH(5 mol/L)-H2O碱性固态聚合物电解质,并以此为电解质和隔膜,以纳米晶N iO为电活性物质组装成碱性全固态纳米晶N iO电化学电容器。采用XRD和HRTEM测试技术结果表明,纳米晶N iO分散性较好,粒径约为5 nm。循安伏安、恒流充放电、交流阻抗、漏电流、自放电和循环寿命等电化学测试均表明,基于PVA-KOH(5 mol/L)-H2O电解质和纳米晶N iO的碱性全固态电化学电容器具有良好的电化学电容特性。当电流密度为0.2 A/g时,其比电容和比能量分别为103.2 F/g和11.6 kW/kg。经过1 500次恒流循环充放电,比电容衰减为初始容量的10%,显示其具有良好的电化学稳定性。

Nanocrystalline NiO was synthesized by pyrolysis of Ni （OH）2 precursor at 300℃, and alkaline solid polymer electrolyte, PVA-KOH （5 mol/L ）-H2O, was prepared via solution-casting technique, and alkaline NiO-based all-solid-state supercapacitor was fabricated with the nanocrystalline NiO as electroactive material and the alkaline solid polymer electrolyte as electrolyte and spacer. XRD and HRTEM demonstrated that the size of the nanocrystalline NiO with good dispersion was ca. 5 nm. Cyclic vohammgoram, galvanostatic charge-discharge, A.C. impedance, leakage current, self-discharge and cycle life tests indicated that all the alkaline all-solid-state supercapacitor exhibited good electrochemical capacitance performance. The specific capacitance and energy density of the supercapacitor were 103.2 F/g and 11.6 kW/kg, respectively, at a current density of 0. 2 A/g. Also, the all-solid-state supercapacitor exhibited a good electrochemical stability with a capacitance degradation of 10% over 1 500 cycles.