Nanowerk April 29, 2023
An international team of researchers (Germany, USA – Northwestern University) studied an alloy of niobium, iron and antimony that converts waste heat into electricity at temperatures ranging from about 70 to more than 700 degrees Celsius with an efficiency of eight percent. To further increase the efficiency of the thermoelectric made of niobium, iron and antimony, the researchers focused on its microstructure. As grain boundaries reduce both the thermal and electrical conductivity of the material, for the highest possible efficiency, the thermal conductivity should be as low as possible so that the heat in the material and the electrical conductivity should be high to convert as much heat as possible into electricity. To optimize the grain boundaries, they enriched the material with titanium which, accumulated at the grain boundaries and increased electrical conductivity by up to 40 percent. To further increase the efficiency the team is analyzing ways to selectively add titanium only to grain boundaries without enriching the entire material with titanium. According to the researchers this strategy saves costs and largely preserves the original chemical composition of the thermoelectric material. Their research shows how functional properties can be linked to the atomic structure of a material to specifically optimize certain properties… read more. Open Access TECHNICAL ARTICLEÂ
Atomic arrangement of the GB phases. Credit: Advanced Energy Materials, Volume 13, Issue 13 2204321, 15 February 2023Â