Researchers develop new class of inexpensive thermoelectric materials

"What we've managed to do is synthesise some compounds that have the same composition as natural minerals," said team leader Donald Morelli, a professor of chemical engineering and materials science. "The mineral family that they mimic is one of the most abundant minerals of this type on Earth – tetrahedrites. By modifying its composition in a very small way, we produced highly efficient thermoelectric materials." While some new materials have been discovered as of late, many of these are not suitable for large scale applications because they are derived from rare or sometimes toxic elements, or the synthesis procedures are complex and costly. "Typically you'd mine minerals, purify them into individual elements, and then recombine those elements into new compounds that you anticipate will have good thermoelectric properties," said Morelli. "But that process costs a lot of money and takes a lot of time. Our method bypasses much of that." The researchers' method involves the use of very common materials, grinding them to a powder, then using pressure and heat to compress into useable sizes. "It saves tremendously in terms of processing costs," Morelli added. The researchers believe the breakthrough could pave the way to many new, low cost thermoelectric generation opportunities, with applications that include waste heat recovery from industrial power plants, conversion of vehicle exhaust gas heat into electricity, and generation of electricity in home-heating furnaces.