Researchers from the Colorado School of Mines have discovered that protonic ceramic fuel cells exhibit long-term durability and fuel flexibility needed for a viable alternative fuel source.
The study involved testing eleven different types of fuels:
- Domestic natural gas with hydrogen sulfide
- Domestic natural gas without hydrogen sulfide
The research demonstrated excellent performance and durability across all fuel types, and the findings were published in the journal Nature.
“Protonic ceramic fuel cells (PCFCs) are very fuel flexible,” said the paper’s co-lead author Ryan O’Hayre. “We can feed them all sorts of different real-world fuels and make electricity. That’s very different from other fuel cells that only work on hydrogen. Some high-temperature solid oxide fuel cells (SOFCs) will also run on other fuels, but they’re very finicky. If you feed them fuels other than hydrogen, they are susceptible to contamination and degradation, and their performance drops rapidly with time. Our fuel cells didn’t face those problems with long-term testing.”
According to O’Hayre, these tests were ten times longer than any which had previously been conducted. A custom fuel-cell testing system, designed and built by Mines Ph.D. candidate and co-lead author Chuancheng Duan, allowed for the simultaneous testing of seven cells using different fuels over thousands of hours.
“The longest test was 8,000 hours, which is almost a whole year,” said Duan. “The degradation rate of most of the fuel cells was less than three per cent per 1,000 hours, which meets the requirements of commercial products.”
Researchers are working with Connecticut-based Fuel Cell Energy to scale up the technology and develop a pre-commercial prototype capable of powering an RV or remote cabin. “Based on our current work and achievements, it is time to collaborate with an industrial partner to make commercial products,” said Duan. “In three years, there will be a 500-watt direct-natural gas PCFC stack developed based on our technology. In less than ten years, there will be a 1-kilowatt PCFC stack that could serve as a house power supply, the backup power supply for offices or mobile base stations.”
“This is an excellent example of the fruitful collaborations between Mines and CoorsTek catalyzed in part by their lead support for the new CoorsTek Center for Applied Science and Engineering on campus,” said O’Hayre. David Hook at CoorsTek spearheaded high-temperature XRD studies that helped us better understand the high-temperature behaviour of our protonic ceramic membrane.”