Future cars may eat their own exhaust, converting heat from their emissions into electricity. The conversion can improve fuel economy by reducing an engine’s workload.
One of the group’s biggest challenges is finding a metal that conducts heat poorly, so heat is not transferred from one side of the chip to the other. GM researchers are currently testing something called skutterudite, a mineral made of cobalt, arsenide, nickel, or iron. Rare-earth metals can reduce skutterudite’s thermal conductivity even more, but we all know how problematic rare-earths can be; to solve the problem, researchers are hoping to replace them with “mischmetal” alloys.
Thermoelectric technology has applications beyond powering cars — they could also be used to harness waste heat in homes and power plants, and they could power new generations of solar cells, Xu said. The work is being funded with $1.4 million from the National Science Foundation and the Department of Energy.