Abstract
The capacitive characteristics of activated carbon fabrics (ACFs) coated on the graphite substrates were systematically investigated by means of cyclic voltammetry and the galvanostatic charge-discharge technique. Effects of the PVDF contents in the electronically conductive binder, electrochemical pretreatments, and the electrolytes on the capacitive performance of ACFs were compared in aqueous media. These ACF-pasted electrodes showed the more ideally capacitive responses in 1M NaNO 3 with a specific capacitance of 76 F g -1 when the electronically conductive binder contained 40wt.% PVDF. The specific capacitance of ACF-pasted electrodes reached a maximum in 0.5M H 2 SO 4 (about 153 F g -1 measured at 25 mV s -1 ), due to the presence of a suitable density of oxygen-containing functional groups, when they were subjected to the potentiostatic polarization at 1.8V (versus reversible hydrogen electrode (RHE)) or potentio-dynamic polarization between 1.3 and 1.8 V in NaNO 3 for 20 min. The oxygen-containing functional groups within the electrochemically pretreated ACFs were identified by means of X-ray photoelectron spectroscopy (XPS). © 2003 Elsevier B.V. All rights reserved.