以胡桃壳为前躯体,采用ZnCl2化学活化法制备炭电极材料,研究了活化剂与果壳的不同混合质量比例对炭材料性质的影响,用氮气吸附和傅立叶红外表征活性炭材料的比表面积、孔结构和表面性质,结果表明:活性炭材料表面存在着含氧官能团,为一种高微孔无定形炭材料;以制备的活性炭为电极材料,KOH为电解液构成超级电容器,采用循环伏安、恒流充放电等电化学方法研究了其电化学性能,结果表明:制备的活性炭电极材料表现出理想的电化学电容行为,比电容高达271.0F/g,漏电流和等效串联电阻分别只有0.25mA和0.39Ω,稳定性很高,循环充放电5000次后,电容量仍保持88%以上。
A series of walnut shells-based activated carbons were prepared by chemical activation method with different ratios of ZnCl2/carbon to produce electrode materials for supercapacitor. The prepared carbon samples were characterized by N2 adsorption at 77K and FTIR to evaluate surface area, porosity and surface properties. The resultant carbons were of high microporous materials with numbers of oxygen functional groups on the carbons surface. The electrochemical behavior of the carbon electrode-based capacitors using KOH as electrolyte was investigated by cyclic voltammetry and galvanostatic charge-discharge. The results show that the capacitors have excellent electrochemical properties: high specific capacitance of 271. 0F/g, low leakage current of 0. 25mA, small equivalent series resistance (ECR) of 0.39Ω, high current efficiency over 98% and excellent stability. After 5000-cycle test of charge-discharge, the capacitance can be maintained by 88%.