High-Performing Thermoelectric Material May Improve Clean Energy Research

Researchers at the University of Houston have discovered a new thermoelectric material capable of high performance at temperatures ranging from room temperature to 300 degrees Celsius (573 degrees Fahrenheit) and possibly higher.

The material is reportedly the first new high-efficiency thermoelectric material in 60 years, and could be important for both clean energy research and commercialization at temperatures above 300 degrees Celsius.

“This new material is better than the traditional material, Bismuth telluride, and can be used for waste heat conversion into electricity much more efficiently,” Zhifeng Ren, M.D. Anderson Chair professor of physics at UH, said.

To create the new material, Ren and other members of his laboratory used a combination of magnesium, silver and antimony to generate electricity from heat using the thermoelectric principle. The new work is built on research done in 2012 by M.J. Kirkham, et al, which used magnesium, silver and antimony in equal parts. However, this combination resulted in impurities and poor conducting properties, so Ren and his colleagues modified the mixture to contain slightly less silver and antimony and mixed the elements separately to eliminate the impurities and improve the thermoelectric properties.

“We had much different qualities,” Ren said. “Better, with no impurities, and smaller grain size, along with much better thermoelectric properties.”

The later addition of a small amount of nickel enabled the compound to work even better.

The material is known simply “MgAgSb-based material,” after the chemical names for the elements used to create it. Currently, the material works well up to 300 degrees Celsius, but the UH team is continuing work to improve its efficiency in the hopes of eventually using it to capture heat from power plants, industrial smokestacks and vehicle tailpipes, where temperatures can range from 200 to 1,000 degrees Celsius.

The work was done in collaboration with researchers from the UH Department of Chemistry and the Massachusetts Institute of Technology.