活化剂种类对活性炭结构及性能的影响

摘要

Using petroleum cokes as raw material, and KOH, NaOH, K2CO3 and Na2CO3 as activated agent respectively,activated carbons were prepared in the chemical activation process. The effects of activated agents on the structure of prepared carbon were investigated by tap density and N2 adsorption method, and the electrochemical properties of the activated carbons were determined using two-electrode capacitors in 1 mol/L Et4NBF4/PC electrolyte by LAND battery tester and electrochemical workstation. The results indicate that KOH is the most efficient activated agent, and a high specific surface area of 2 362 m2/g and a high micropore volume of 1.263 cm3/g are obtained in the activated carbon prepared by KOH. Used in supercapacitors, the activated carbon shows a well electrochemical performance, and the specific capacitance is 128.0 F/g. With the decrease of the alkalinity, the activated ability of the agent reduces; K2CO3 and Na2CO3 are not suitable for preparation of activated carbon from petroleum cokes.%以石油焦为前驱体,分别以KOH,NaOH,K2CO3和Na2CO3为活化剂通过化学活化制备活性炭,采用振实密度仪和全自动N2吸附仪研究活性剂对活性炭结构的影响,并以制备的活性炭为电极材料,l mol/LEt4NBF4/PC为电解液组装模拟电容器,采用LAND快速采样电池测试仪和电化学工作站考察不同活化剂对活性炭电化学性能的影响.研究结果表明:KOH具有最强的活化能力,其活化制备的活性炭具有较高的微孔含量和发达的孔隙结构,比表面积达2 362m2/g,孔容达到1.263 cm3/g,以其作电极材料,表现出良好的电容行为,质量比容量最高达到128.0 F/g,随着活化剂碱性的降低,活化能力大幅度降低,制备的活性炭比表面积和孔容急剧减小,K2CO3和Na2CO3不适合用作活化石油焦制备活性炭的活化剂.