化学-物理混合活化法改性活性炭电化学性能

以FeCl3为化学添加剂、CO2为活化剂,采用化学-物理混合活化法对溧阳活性炭(LAC)进行改性。研究了改性后活性炭作为超级电容器电极的电化学性能。实验表明FeCl3-CO2体系可以明显改进活性炭的孔结构和孔径分布,经改性后活性炭平均孔径稍有下降,但BET比表面积和总孔容都较原料炭增加了1倍,孔径分布更趋均匀;经循环伏安测试,比电容量由原来的190F/g提高至355F/g;交流阻抗测试结果表明改性后等效电容量从21F/g提高至48F/g,低频段“电荷饱和”频率从120mHz提高至670mHz,但是也导致了电极界面接触电阻的增大。

Study on modification of active carbon by mixtures of chemical and physical and its electrochemical properties

Li Yang active carbon (LAC) was modified by chemical-physical way with FeCl3 as catalyst and CO2 as active agent. The electrochemical performance of active carbon was studied. The experiment results show that the pore structure and pore distribution of the active carbon can be obviously improved by using FeCl3-CO2 system. The average pore diameters of active carbon become smaller and pore distribution more even after modification. The BET specific surface area, however, increases to twice. The cyclic voltammetry tests show that the specific capacitance increases from 190 F/g to 355 F/g after modification. AC impedance analysis displays that the modification can raise the capacitance from 21 F/g to 48 F/g and the frequency of charge saturation from 120 mHz to 670 mHz, but result in increasing of the contact resistance between interfaces.