초록 ▼

The present invention contemplates a PEM fuel cell having electrical contact elements (including bipolar plates/septums) comprising a titanium nitride coated light weight metal (e.g., Al or Ti) core, having a passivating, protective metal layer intermediate the core and the titanium nitride. The pro

The present invention contemplates a PEM fuel cell having electrical contact elements (including bipolar plates/septums) comprising a titanium nitride coated light weight metal (e.g., Al or Ti) core, having a passivating, protective metal layer intermediate the core and the titanium nitride. The protective layer forms a barrier to further oxidation/corrosion when exposed to the fuel cell's operating environment. Stainless steels rich in CR, Ni, and Mo are particularly effective protective interlayers.

대표청구항 ▼

[ What is claimed is:] [3.]3. In a bipolar PEM fuel cell having a plurality of cells each comprising an anode, a cathode, a membrane electrolyte interjacent said anode and cathode for conducting ions therebetween, and a plurality of electrically conductive contact elements engaging said anodes and c

[ What is claimed is:] [3.]3. In a bipolar PEM fuel cell having a plurality of cells each comprising an anode, a cathode, a membrane electrolyte interjacent said anode and cathode for conducting ions therebetween, and a plurality of electrically conductive contact elements engaging said anodes and cathodes for conducting electrical current therefrom, the improvement comprising said contact elements each comprising a metal core selected from the group consisting of aluminum and titanium, a stainless steel protective coating on said core, and a titanium nitride topcoat atop said stainless steel protective coating, a plurality of defects in said topcoat exposing said protective coating to a corrosive operating environment within said fuel cell, said stainless steel coating containing sufficient chromium, nickel and molybdenum as to be susceptible to oxidative passivation by said corrosive operating environment so as to form a barrier to further oxidation/corrosion on the portions of such coating as are exposed to said environment, whereby said core is protected from corroding by said stainless steel underlying said defects. [5.]5. The bipolar fuel cell according to claim .[.1.]. .Iadd.3 .Iaddend.wherein said stainless steel comprises by weight at least 16% Cr, at least 20% Ni, and at least 3% Mo.