Durable hydrophilic coatings for fuel cell bipolar plates

The fuel cell according to claim 4 wherein the metal oxide comprises at least one of SiO2, HfO2, ZrO2, Al2O3, SnO2, Ta2O5, Nb2O5;

• MoO2, IrO2, RuO2, metastable oxynitrides, nonstoichiometric metal oxides, oxynitrides and mixtures thereof.

A fuel cell comprising:

• a perfluorosulfonic acid membrane that generates hydrofluoric acid;
• and
• a flow field plate being made of a plate material, said flow field plate including a plurality of flow channels responsive to a reactant gas, said flow field plate further including an outer metal oxide layer that makes the flow field plate hydrophilic, wherein the particular metal oxide in the metal oxide layer and the thickness of the metal oxide layer are selected so that the hydrofluoric acid etches away an outer surface of the layer at a desirable rate so that a clean surface of the layer is continuously exposed, but the layer is not completely etched away over a predetermined lifetime of the fuel cell.

A method for making a flow field plate for a fuel cell, said method comprising:

• providing a flow field plate being made of a plate material, said flow field plate including a plurality of flow channels;
• and
• depositing an outer layer on the plate that makes the flow field plate hydrophilic, wherein depositing an outer layer on the plate includes depositing the layer so that the material of the layer and the thickness of the layer cause hydrofluoric acid within the fuel cell to etch away an outer surface of the layer at a rate so that a clean surface of the layer is continuously exposed, but the layer is not completely etched away over a predetermined lifetime of the fuel cell.