SwedEN-based product developer Impact Coatings has developed a new material for the coating of fuel cell bipolar plates, which could change the economics of fuel cells by significantly reducing manufacturing costs.
The cost of bipolar plates is regarded as one of the main obstacles to widespread commercialisation of fuel cell technology and Impact Coatings’ Ceramic MaxPhase development provides an alternative to coating the metal bipolar plates with gold or graphite.
Thin gold plating for coating bipolar metal plates in fuel cells costs about $12/kW and graphite about $7/kW, and Impact Coatings CEO Henrik Ljungcrantz says the Ceramic MaxPhase coating will reduce the cost to about $5/kW and the cost is expected to be less than the US Department of Energy’s target of $1/kW by 2017.
Bipolar plates are used as anodes and cathodes in fuel cells, connecting several cells into a stack to produce the desired voltage. The plates are prone to corrosion, owing to the aggressive environment inside the fuel cell.
The ceramic coating is less bulky than graphite and cheaper than gold-plated plates. It is also a corrosion-resistant, electrically conductive ceramic coating that is applied through physical vapour disposition. The material has been certified for use in proton-exchange membrane fuel cells and direct methanol fuel cells in tests that exceeded 2 500 hours. The bipolar plates of stainless steel coated with Ceramic MaxPhase showed equivalent stack performance to gold-plated bipolar plates during testing.