Promising new material to improve gas mileageOctober 10th, 2008 - 3:08 pm ICT by IANS
Washington, Oct 10 (IANS) Three-quarters of the potential energy in the oil that you are paying for is wasted, much of it going right out of the tailpipe instead of powering your car.Now a Northwestern University-led research team has identified a promising new material that could transform a technology that cools and heats car seats — thermoelectrics — into one that also efficiently converts waste heat into electricity to help improve gas mileage.
“We cannot explain this 100 percent, but it gives us a new mechanism — and probably new science — to focus on as we try to raise the efficiency of thermoelectrics,” said Mercouri G. Kanatzidis, chemistry professor at the Weinberg College of Arts and Sciences and the paper’s co-author.
Researchers discovered that adding two metals, antimony and lead, to the well-known semiconductor lead-telluride, produces a thermoelectric material that is more efficient at high temperatures than existing materials, according to a Northwestern press release.
Current thermoelectric technology is only used in niche markets, such as solid-state refrigeration and cooling, because the materials are not very efficient. With new materials and increased efficiency, devices based on thermoelectrics could find widespread use in the automotive industry, solar energy conversion and the conversion of waste heat from nuclear reactors, smokestacks and industrial equipment.
“It’s a big accomplishment to recover some of the heat or energy that would otherwise be lost and convert it into useful energy,” said Kanatzidis. “That’s what thermoelectrics can do, but we need to make them more efficient to really be practical.”
Thermoelectric materials are only five to six percent efficient today, but a new generation of materials based on recent discoveries including this one at Northwestern, could produce devices with 11 to 14 percent efficiency, said Kanatzidis. The long-term goal is to reach 20 percent.
The results were published online in Angewandte Chemie.