Nano-tailored coatings for cost-efficient PEM fuel cell bipolar plates

Stainless steel bipolar plates make PEM fuel cell stacks significantly thinner and cheaper, but steel corrodes under the operating conditions of a hydrogen fuel cell. Released iron poisons the membrane and the surface oxide raises contact resistance, leading to poor performance. Today plates are either made of carbon polymer or protected with expensive coatings that are slow to deposit.

NANOFIT validates NacoICR, Naco Technologies' three-layer nano-coating for stainless steel bipolar plates, in stacks of compact PEM fuel cells developed for aviation, maritime and stationary use. 

NacoICR combines an adhesion layer, a dense bimetallic nitride barrier and a nanometric conductive top layer, deposited by Naco's high-speed magnetron sputtering (HMS), a proprietary dry vacuum process up to 10x faster than conventional coating processes.

Four industrial partners have already tested our coating at cell level: NacoICR showed corrosion resistance and electrical conductivity on a par with gold plating, and the lowest degradation among eight competing coatings. With a European fuel cell manufacturer, Naco will now coat full-size plates of the partner's design, build them into a stack and run at least 1000 hours under a real load profile. That takes NacoICR from TRL 6 to TRL 7.