活性炭二次活化对其电化学容量的影响

为进一步提高作为电化学超级电容器电极材料活性炭的电化学容量, 采用KOH作为二次活性剂, 将所得活性炭进行二次化学活化处理, 从而得到二次活化活性炭. 将原始活性炭材料与二次活化活性炭材料都分别经过系列处理, 组装成电化学超级电容器进行电化学性能测试. 测试结果表明, 二次活化活性炭材料的电化学容量达到145.0 F·g-1(有机电解液), 远远大于原活性炭材料的容量(45.0 F·g-1). 为研究二次活化活性炭材料电化学容量大幅提高的原因, 将这两种材料分别进行微观结构数据测试, 包括比表面积、N2吸脱附等温曲线和孔径分布. 研究结果表明, 二次活化处理大大增加了二次活化活性炭材料在孔径为2-3 nm的中孔分布, 从而证实对于有机电解液, 电极材料在2-3 nm的中孔对其电化学容量的提高具有重要意义.

Effect of the Activated Carbon Reactivation on Its Electrochemical Capacitance

To enhante the electrochemical capacitance of activated carbon(AC),which is used as the electrode material for electrochemical super capacitors(ESC),the AC material was reactivated using chemical activation method and KOH as reactivation agent.The obtained material was designated as reactivated AC.Pristine AC and reactivated AC were both Used as ESC electrode materials and simulated ESCs were assembled to test their electrochemical performance.Results showed that the electrochemical capacitance of the reactivated AC was enhanced up to 145.O F·g-1 in organic electrolyte,while the pristine AC only obtained a value of 45.0 F·g-1.To determine the reason for the enhancement of the samples electrochemical capacitance,the specific surface area,N2 adsorption-desorption isotherms, and pore diameter distributions were investigated.Results showed that reactivation treatment enhanced the pore distribution content of 2 to 3 nm(pore diameter).Pores with diameters from 2 to 3 nin(pore diameter)are thus important in the carb on material's electrochemical capacitance using organic electrolyte.