Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7740924 | Journal of Power Sources | 2013 | 7 Pages |
Abstract
A highly porous carbon xerogel was synthesized by means of physical activation. The activated carbon xerogel, which displayed a well-developed porous texture (micro- and meso-porosity), was employed as electrode material in different supercapacitors. In assessing the performance of the supercapacitors, special attention was paid to their dimensions and the type of electrolyte used. Both the method of electrode manufacture (rolling and punching of 1Â cm2 pellets vs. casting by means of a film applicator to produce 4Â cm2 electrodes) and the type of supercapacitor (Swagelok (R) system vs. cell with graphite plate current collectors) were evaluated. The results reveal that the cells with larger electrodes were able to store higher amounts of energy. In addition to the cells, the electrochemical characteristics in aqueous electrolytes with a different pH were studied (H2SO4, Na2SO4 and KOH, 1Â M). The highest capacitance values were achieved with sulphuric acid (196Â FÂ gâ1 as opposed to 140 and 106Â FÂ gâ1 for Na2SO4 and KOH, respectively), probably due to its higher ionic conductivity and the basic nature of the oxygen functionalities found on the surface of the carbon xerogel. Nevertheless, because of the corrosive character of sulphuric acid, Na2SO4 would be a more suitable electrolyte.
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Authors
E.G. Calvo, F. Lufrano, P. Staiti, A. Brigandì, A. Arenillas, J.A. Menéndez,