New ceramic-carbon composites for electrodes for electrochemical capacitors.

A new class of composite materials is introduced. Fine powders of silica, titania, Y-modified zirconia, and three types of alumina were pressed and sintered to form porous monoliths with relatively uniform pore structure. Carbon was then deposited in the pores of such monoliths by thermal decomposition of dichloromethane, cyclohexene, and glucose. The structure of the carbon deposit was studied by low-temperature nitrogen adsorption and by thermal analysis. The composite materials were used as electrodes in electrochemical capacitors with 1-ethyl-3-methylimidazolium trifluoromethylsulfonate (a low-temperature ionic liquid) as the electrolyte. High capacitances were observed for glucose-derived materials, which had high specific surface areas.