A sandwich-type supercapacitor consisting of two similar activated carbon fabric-polyaniline (ACF-PANI) composite electrodes was demonstrated to exhibit excellent performance (i.e., highly reversibility and good stability) in NaNO3. Polyaniline with the charge density of polymerization less than or equal to 9 C cm(-2) synthesized by means of a potentiostatic method showed a high specific capacitance of 300 F g(-1). Influences of the polymerization charge density (i.e., the polymer loading) on the capacitive characteristics of ACF-PANI omposites were compared systematically. The capacity of an ACF-PANI electrode reach ca. 3.4 F cm(-2) (a 100% increase in total capacity) when the charge density of polymerization is equal to 9 C cm-2. The surface morphology of these ACF-PANI composites was examined by a scanning electron microscope (SEM). (C) 2004 Elsevier B.V. All rights reserved.