Supercapacitors with improved energy and power densities have been constructed with anthraquinone modified carbon fabric (Spectracarb 2225) as the negative electrode and unmodified carbon fabric as the positive electrode. A Nafion separator and 1M sulfuric acid electrolyte were employed. The performances of the supercapacitors were characterized by cyclic voltammetry and constant current discharging. Use of the anthraquinone modified electrode as the negative electrode (anode during discharge) in the supercapacitor provides 40% higher average capacitance, 56–86% higher energy density, and improved power duration.