United Technologies Corporation

Larry G Christner

Dennis C Nagle

Paul R Watson

A ribbed electrode substrate for an electrochemical cell comprises a gas porous substrate having ribs of hydrophilic material extending across one side thereof. The other side of the substrate is substantially flat and may have a catalyst layer disposed thereon. In one embodiment a stack of fuel cells uses electrodes having these ribbed substrates. A flat, gas impermeable plate separates the electrode substrates of adjacent cells, the ribs of each substrate abutting opposite surfaces of the plate forming channels for carrying reactant gas across the cells. Electrolyte is stored in the ribs, which are hydrophilic. The electrolyte in the ribs moves to and from the electrolyte matrix of the cell by capillary action through the substrate.

Electrochemical cell comprising a ribbed electrode substrate

A method for fabricating porous carbon sheet material and in particular for fabricating porous carbon fuel cell electrode substrates comprises coating carbon fibers with a mixture of furfuryl alcohol and a catalyst which polymerizes furfuryl alcohol, forming the fibers into a mat or sheet of the desired size and thickness, heating the mat to polymerize the furfuryl alcohol and to cure the resin so formed, and further heating the mat to carbonize the resin. Phosphoric acid is the preferred polymerization catalyst when the sheet material is to be used as a fuel cell electrode substrate. The method produces electrode substrates which are highly porous yet strong and which are also corrosion resistant, thermally conductive and electrically conductive.

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Glastonbury, CT, United States of America

Larry G Christner