文献类型：期刊文献

英文题名：Ion Intercalation into Graphitic Carbon with a Low Surface Area for High Energy Density Supercapacitors

作者：Zhang, Chuanfang[1,2];Xie, Yingbo[3];Sun, Gangwei[1];Pentecost, Amanda[2];Wang, Jitong[1];Qiao, Wenming[1];Ling, Licheng[1];Long, Donghui[1];Gogotsi, Yury[2]

机构：[1]E China Univ Sci & Technol, Dept Chem Engn, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[2]Drexel Univ, Dept Mat Sci & Engn, AJ Drexel Nanomat Inst DNI, Philadelphia, PA 19104 USA;[3]Titanchem Co LTD, Shanghai 200237, Peoples R China

年份：2014

卷号：161

期号：10

起止页码：A1486

外文期刊名：JOURNAL OF THE ELECTROCHEMICAL SOCIETY

收录：;EI(收录号：20143518094726);WOS:【SCI-EXPANDED(收录号:WOS:000341217500003)】；

基金：This work was partly supported by MOST (2014CB239702) and National Science Foundation of China (No. 51302083, No. 51172071, No. 51272077), and Fundamental Research Funds for the Central Universities and Shanghai Pujiang Program, and Program of Shanghai Subject Chief Scientist (B type, No 13XD1424900). C. Zhang is supported by Chinese Scholarship Council (CSC). Z. Ling is acknowledged for helpful data discussion.

语种：英文

外文关键词：Supercapacitor - Electric discharges - Ions - Potassium hydroxide - Capacitance - Cyclic voltammetry - Chemical activation - Petroleum coke

摘要：Commercial porous activated carbons have a high surface area and gravimetric capacitance but a low pack density. In this work, highly ordered graphitic carbons with different microcrystalline structures were prepared by the calcination and KOH-activation of petroleum coke. When the graphitic carbons were electrochemically activated at 4 V, specific capacitance was increased to 166 F/g from a very low initial value caused by the low surface area. The energy and power density reached 48.5 Wh/kg (32.8 Wh/L) and 6106 W/kg (4132.4 W/L), respectively, at 3.3 A/g. Electrochemical activation is believed to be a voltage-driven ion intercalation process, in which abundant ion-accessible sites are created and can be used for mixed ion adsorption/intercalation charge storage. The effects of solvents, applied voltage, and cation selection on the ion intercalation behavior were systematically studied using galvanostatic charge-discharge and cyclic voltammetry techniques. The results revealed that higher applied voltage, shorter chain length, and weaker solvent-ion interactions favor ion intercalation to the positive and negative electrodes, consequently leading to symmetrical capacitive responses and maximum cell performance. (C) 2014 The Electrochemical Society. All rights reserved.