Competitive effect of KOH activation on the electrochemical performances of carbon nanotubes for EDLC: Balance between porosity and conductivity
Competitive effect of KOH activation on the electrochemical performances of carbon nanotubes for EDLC: Balance between porosity and conductivity
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DOI：
10.1016/j.electacta.2008.05.033
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发表时间：
2008-11
影响因子：
6.6
通讯作者：
Bin Xu;Feng Wu;Yuefeng Su;Gaoping Cao;Shi Chen;Zhi-Mimg Zhou;Yusheng Yang
中科院分区：
文献类型：
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作者：
Bin Xu;Feng Wu;Yuefeng Su;Gaoping Cao;Shi Chen;Zhi-Mimg Zhou;Yusheng Yang
本工作的重点是对双电层电容器（EDLC）的性能之间的竞争效应的孔隙率增加，同时电导率降低KOH活化的碳纳米管（CNT）。一系列的碳纳米管已被激活与KOH，以提高其在EDLC应用的表面积。通过N2吸附、透射电镜（TEM）观察和电导率测定对活性碳纳米管（ACNTs）的微观结构进行了表征。采用恒电流充放电、循环伏安、交流阻抗等测试手段，研究了它们在KOH水溶液中的电化学性能。结果表明，KOH活化提高了碳纳米管的比表面积和比电容，但降低了其电导率和双电层电容器的倍率性能。通过控制碳纳米管的活化，平衡孔隙率和电导率，获得了同时具有高电容和良好倍率性能的ACNTs。
This work is focused on the competitive effects on the performance of the electric double layer capacitors (EDLCs) between porosity increase and simultaneous conductivity decrease for KOH-activated carbon nanotubes (CNTs). A series of the CNTs have been activated with KOH to enhance their surface areas for application in EDLCs. The microstructure of the activated carbon nanotubes (ACNTs) is characterized with N2adsorption, transmission electron microscopy (TEM) observation and electric conductivity measurement. Their electrochemical performances are evaluated in aqueous KOH electrolyte with galvanostatic charge/discharge, cyclic voltammetry, and ac impedance spectroscopy. It is found that the KOH activation enhances the specific surface area of the CNTs and its specific capacitance but decreases its electric conductivity and the rate performance in EDLC. By controlling the activation of the CNTs to balance the porosity and conductivity, ACNTs with both high capacitance and good rate performance are obtained.