METHOD TO MAKE CONDUCTIVE HYDROPHILIC FUEL CELL ELEMENTS

摘要

A flow field plate for a fuel cell that has one or more outer layers that makes the plate more conductive and hydrophilic. In one embodiment, the coating is co-deposited as combination of a conductive material and a metal oxide coating. A suitable conductive material is gold and suitable metal oxides include SiO₂, HfO₂, ZrO₂, AI2O₃, SnO₂, Ta2O₅, Nb2O₅, MoO₂, IrO₂, RuO₂ and mixtures thereof. The conductive material and metal oxide can also be deposited as two separate layers, where the metal oxide is the outer layer. According to another embodiment, a metal layer is deposited on the plate with nanopores that provide the hydrophilicity. Also, doping ions can be added to the metal oxide to provide low fluoride solubility of the coating to control the rate that hydrofluoric acid etches away the oxide layer.