Hold onto your hats, folks, because the energy world just got a whole lot more exciting. Researchers at Michigan Technological University have created a new type of fuel cell that promises to revolutionize the industry. Yun Hang Hu and his team have developed a carbonate-superstructured solid fuel cell (CSSFC) that uses hydrocarbon fuel directly rather than relying on the expensive process of reforming hydrogen.
Fuel cells work by producing energy through an electrochemical process, but unlike batteries, they don’t run down or require recharging. However, the potential advantages of fuel cells are offset by challenges that include cost, performance, and durability. That’s where the CSSFC comes in. By creating an interface between the electrolyte and melted carbonate, Hu and his team have created an ultrafast channel for oxygen ion transfer, increasing efficiency and performance.
The CSSFC has a wide array of potential uses, from providing energy to operate fuel cell vehicles and home power generation to entire power stations. And because it’s fuel flexible, it offers higher durability and energy conversion efficiency at lower operating temperatures than other types of fuel cells.
But that’s not all. The CSSFC’s electrochemical performance at lower operating temperatures offers several other advantages. “The operating temperature of a conventional solid oxide fuel cell is usually 800 degrees Celsius or higher, because ion transfer in a solid electrolyte is very slow at a lower temperature,” Hu said. “In contrast, the CSSFC’s superstructured electrolyte can provide a fast ion transfer at 550 degrees Celsius or lower — even as low as 470 degrees Celsius.”
Tests on the CSSFC also showed an unprecedentedly high open circuit voltage (OCV), which indicates no current leakage loss and high energy conversion efficiency. Hu estimates that CSSFC fuel efficiency could reach 60%, compared to the average fuel efficiency of a combustion engine, which ranges between 35% and 30%. The CSSFC’s higher fuel efficiency could lead to lower vehicle carbon dioxide emissions.
Hu and his team began looking at methods to improve solid oxide fuel cells (SOFCs) four years ago. In addition to addressing issues associated with SOFC operating temperatures — an industrywide goal — they examined the unique properties of superstructured materials. Created with specific forms to serve specific functions, SOFCs have wide applications in science and engineering.
Lower operating temperatures with hydrocarbon fuels are problematic because they result in slow fuel oxidation and cause coking — when accumulated carbon deposits gunk up fuel cells, degrading efficiency and performance. “Hydrocarbon oxidation kinetics are extremely sluggish at lower temperatures due to the strong carbon-hydrogen bonds,” Hu said. “Carbon deposition also deactivates the electrodes by covering their catalytic sites.”
To test their hypothesis, researchers fabricated a device in the lab. “In our experiments, the CSSFC exhibited ultrahigh oxygen ionic conductivity at 550 degrees Celsius, achieving rapid oxidation of hydrocarbon fuel. This led to an unprecedented high open-circuit voltage of 1.041 volts and a very high peak power density of 215 milliwatts per square centimeter, along with excellent coking resistance using dry methane fuel,” said Hu.
The potential for the CSSFC is huge, and Hu and his team are already looking to new frontiers, including creating superstructured materials as a new platform for energy devices. The CSSFC is fueling excitement in the energy industry, and we can’t wait to see where it takes us.