標題: | Supercapacitive Properties of Micropore- and Mesopore-Rich Activated Carbon in Ionic-Liquid Electrolytes with Various Constituent Ions |
作者: | Quoc Dat Nguyen Patra, Jagabandhu Hsieh, Chien-Te Li, Jianlin Dong, Quan-Feng Chang, Jeng-Kuei 材料科學與工程學系 Department of Materials Science and Engineering |
關鍵字: | carbon;electric double-layer;ionic liquids;pore size;supercapacitors |
公開日期: | 24-一月-2019 |
摘要: | Ionic-liquid (IL) electrolytes, characterized by large potential windows, intrinsic ionic conductivity, low environmental hazard, and high safety, are used for micropore- and mesopore-rich activated-carbon (AC(micro) and AC(meso)) supercapacitors. IL electrolytes consisting of various cations [1-ethyl-3-methylimidazolium (EMI+), N-propyl-N-methylpyrrolidinium (PMP+), and N-butyl-N-methylpyrrolidinium (BMP+)] and various anions [bis(trifluoromethylsulfonyl)imide (TFSI-), BF4-, and bis(fluorosulfonyl)imide (FSI-)] are investigated. The electrolyte conductivity, viscosity, and ion transport properties at the AC(micro) and AC(meso) electrodes are studied. In addition, the capacitance, rate capability, and cycling stability of the two types of AC electrodes are systematically examined and post-mortem material analyses are conducted. The effects of IL composition on the charge-discharge capacitances of the AC(micro) electrodes are more pronounced than those for the AC(meso) electrodes. The FSI-based IL electrolytes, for which electrochemical properties are cation dependent, are found to be promising. Incorporating EMI+ with FSI- results in a low electrolyte viscosity and a fast ion transport, giving rise to optimized electrode capacitance and rate capability. Replacing EMI+ with PMP+ increases the cell voltage (to 3.5 V) and maximum energy density (to 42 Wh kg(-1)) of the AC(micro) cell at the cost of cycling stability. |
URI: | http://dx.doi.org/10.1002/cssc.201802489 http://hdl.handle.net/11536/148931 |
ISSN: | 1864-5631 |
DOI: | 10.1002/cssc.201802489 |
期刊: | CHEMSUSCHEM |
Volume: | 12 |
起始頁: | 449 |
結束頁: | 456 |
顯示於類別: | 期刊論文 |