Interconnects are sandwiched between fuel cell layers to provide support and to help conduct electricity through the fuel cell stack. The interconnects corrode easily, leading to failures. Paul Gannon and others are investigating protective metal coatings as a way of extending interconnect lifetimes.

Fuel cells:
big challenges, great potential

Fuel cells have been around about 150 years. They're efficient and clean energy sources but haven't been widely adopted because they're expensive and not very durable.

A kilowatt of electricity from today's fuel cells costs about $3,000 to produce, according to Gary McVay at the Pacific Northwest National Lab. At about $1,000 per kilowatt, certain niche markets open up. But to be competitive with other methods of power generation, the price tag must be about $400 per kilowatt.

"There are fuel cell development companies out there, but most are not mass producing yet," said MSU graduate student Paul Gannon. "So we need new technology aimed at mass producing to make the price lower."

The materials are what keeps the cost high, which is why Gannon is on the job. He's investigating pieces of stainless steel called interconnects that help conduct electricity through solid oxide fuel cell stacks. To keep the interconnects from corroding in the harsh, 1500 degree Fahrenheit fuel cell environment, Gannon and other are investigating protective coatings. "Everyone doing stack development is finding corrosion problems," said PNNL lab fellow Larry Pedersen.

Interconnects of coated stainless steel components will be much cheaper to produce than ones made from expensive alloys or ceramics, Pedersen said.

The chromium/aluminum coatings are applied on 4"x 4" pieces of stainless steel in the thinnest layers imaginable ( a few micrometers) at Arcomac Surface Engineering, a high-tech company in Bozeman that has a deposition machine like none other in the world.

Then Gannon stacks the squares like sandwiches and loads them into kilns. He heats them to 1500 degrees for 1200 hours (50 days) to see how well the coatings perform. That information informs the development and testing of new coatings. Gannon's tested about 20 coatings so far.

An acceptable interconnect would have to last 40,000 hours with just a two percent failure rate in the first 1,000 hours, said Pedersen.

Cost, flexibility, expertise spur MSU's fuel cell research

Fuel cells come in five types: solid oxide; molten carbonate; alkaline; phosphoric acid; and proton exchange membrane.

MSU began its solid oxide fuel cell program about two years ago for several reasons, said Lee Spangler, who coordinates the program. For one, solid oxide fuel cells operate at high temperatures (1500 degrees Fahrenheit), meaning nonprecious metals can be used as catalysts to drive the production costs down.

For another, solid oxide fuel cells are more fuel-flexible. They can tolerate chemical byproducts that would poison other fuel cell types. Finally, MSU faculty have the right expertise in solid oxide fuel cell materials and chemistry as well as power engineering.

Funded at about $1-million a year, the fuel cell program at MSU involves seven faculty and 13 graduate students. Up to 18 MSU undergraduates as well as a few high school teachers and students have worked on the program, too.

The funds come from the U.S. Department of Interior and were appropriated to Montana with the help of Sen. Conrad Burns.

MSU offered its first class on fuel cells last year and is one of just a few universities in the country putting together a curriculum on the topic, said Robert Marley, dean of the College of Engineering. An entire workforce needs to be trained to design, implement and maintain fuel cells as the country moves toward this more efficient means of energy production, he said.

MSU also is the first satellite research center for the Department of Energy's High-Temperature Electrochemistry Center, which is working toward creating highly efficient, pollution- free power plants by 2015.

The MSU faculty involved in the research are: