硝酸改性活性炭电极材料的电化学性能研究

Study on the Electrochemical Performance of Activated Carbon Electrode Material Modified by Nitric Acid

以浓度为65%的硝酸对商品活性炭进行改性,利用傅里叶-红外光谱和N_2吸附-脱附仪分别表征改性前后活性炭电极材料的表面化学性质和孔结构参数,用循环伏安、恒流充放电和交流阻抗等电化学方法研究了它们在6 mol·L^(-1)KOH电解液中的电化学性能.结果表明,尽管改性活性炭的比表面积和孔径参数均有一定程度下降,但其比电容却增加,高达254.3 F·g^(-1),比改性前提高了18.0%.同时,活性炭的频率响应特性增强,电阻明显减小.

The modification of a commercial activated carbon （CAC） was carried out by using 65 % nitric acid. The FT-IR spectroscopy and nitrogen adsorption-desorption at 77 K were used to characterize the surface chemistry and pore parameters of the experimented carbon samples, respectively. Their electrochemical properties were evaluated in 6 mol · L^-1 KOH as the electrolyte by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy. The results showed that the specific capacitance of the modified carbon could be as high as 254. 3 F · g^-1, 18. 0% higher than that of CAC, frequency response of carbon electrode could markedly enhance and electronic resistance could obviously decrease.