Correlation between Pore Structure andElectrochemical Capacitance of Nanoporous Carbon Electrodes
| Autor: | Kai-Ping Wang, 王凱平 |
|---|---|
| Rok vydání: | 2005 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 93 The present work has demonstrated a simple and applicable method for preparing mesoporous carbon with mesoporous silica as template. The carbon was shown to be a potential material as electrochemical capacitor electrode of its high surface area and electric conductivity. After activation of the mesoporous carbon, the resulting carbon was subjected to electrochemical analysis, which included cyclic voltammetry, galvanostatic chargeand discharge, and a.c. impedance measurement. The specific capacitance of mesoporous carbon electrode increased with surface area to reach a limit value, and then decreased with further surface area increase. Mesoporous carbon was higher than granular activated carbon on the specific capacitance and the capacitance per unit area. It indicated that mesoporous carbon has supplied a pathway for electrolyte diffusion, and this would speed up the complete formation of double layer. Therefore, mesoporous carbon possessed high capacitance even at high charge/discharge rates. In addition, the capacitance of the mesoporous carbon can be improved up to 30% after nitric acid treatment. Carbon powder derived from activated carbon cloth was also shown to own high capacitance as well The length of micropores in the powder was shorter than that in activated carbon powder, leading to a high degree of pore accessibility to the electrolyte ions The high capacitance was still preserred at high charge/discharge rates. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
|