文献类型：期刊文献

英文题名：Asymmetric capacitance response from the chemical characteristics of activated carbons in KOH electrolyte

作者：Sun, Gangwei[1];Long, Donghui[1];Liu, Xiaojun[1];Qiao, Wenming[1];Zhan, Liang[1];Liang, Xiaoyi[1];Ling, Licheng[1]

机构：[1]E China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China

年份：2011

卷号：659

期号：2

起止页码：161

外文期刊名：JOURNAL OF ELECTROANALYTICAL CHEMISTRY

收录：;EI(收录号：20112814143529);WOS:【SCI-EXPANDED(收录号:WOS:000293481700006)】；

基金：This work was partly supported by National Science Foundation of China (No. 50730003), National Project of Scientific and Technical Supporting Programs funded by Ministry of Science & Technology of China (No. 2007BAE55B00), National High Technology Research and Development Program of China (No. 2007AA0 5Z31 1), and Program for New Century Excellent Talents in University (NCET-07-0285).

语种：英文

外文关键词：Electrochemical capacitors; Oxygen-containing functional groups; Pseudo-capacitance; Inorganic electrolyte; Asymmetric capacitance response

摘要：The positive and negative capacitance behaviors of heat-treated activated carbons are separately studied in a three-electrode configuration using 6 M KOH and 1 M H2SO4 as electrolytes. Heat treatment of activated carbons at 400-800 degrees C causes slight changes in surface area accompanied by a significant removal of oxygen-containing functional groups. Consequently, the specific surface capacitance with a 25% reduction in the negative and an 8% reduction in the positive are monitored in KOH electrolyte. The unequal capacitance reductions as well as the asymmetric CV curves reveal that the negative pseudo-capacitances are much larger than the positive ones in KOH electrolyte. These results could be ascribed to the redox reactions preferring in the negative region. The insertion process of cation also plays a significant effect on the asymmetric capacitance behavior. Compared with the identical electrochemical response in H2SO4 electrolyte, huge difference in the capacitance values of both electrodes in KOH electrolyte will give a less contribution to the cell capacitance. To optimize the cell performance, a suitably increasing the weigh of active materials in the positive, especially for activated carbon with high level of oxygen-containing functional groups, is recommended. (C) 2011 Elsevier B.V. All rights reserved.