Development of Carbon‐Metal Oxide Supercapacitors from Sol‐Gel Derived Carbon‐Ruthenium Xerogels

Sol‐gel derived high surface area carbon‐ruthenium xerogels were prepared from carbonized resorcinol‐formaldehyde resins containing an electrochemically active form of ruthenium oxide. The electrochemical capacitance of these materials increased with an increase in the ruthenium content indicating the presence of pseudocapacitance associated with the ruthenium oxide undergoing reversible faradaic redox reactions. A specific capacitance of 256 F/g (single electrode) was obtained from a carbon xerogel containing 14 wt % Ru, which corresponded to more than 50% utilization of the ruthenium. The double layer accounted for 40% of this capacitance. This material was also electrochemically stable, showing no change in a cyclic voltammogram for over 2000 cycles. © 1999 The Electrochemical Society. All rights reserved.