DURABLE HYDROPHILIC COATINGS FOR FUEL CELL BIPOLAR PLATES

摘要

A flow field plate for a fuel cell that includes an outer layer of a metal oxide or other material that makes the plate hydrophilic. The particular metal oxide and the thickness of the metal oxide layer are selected so that hydrofluoric acid generated by the fuel cell continuously etches away the layer at a predetermined rate so that a surface of the layer is free of contaminants over the entire life of the fuel cell. If the fuel cell does not employ a perfluorosulfonic acid membrane, then a separate hydrofluoric acid source can be provided that injects a low level solution of hydrofluoric acid into one or both of the reactant gas streams.