Energy Savings as Easy as Dirt, Heat, Pressure
By using common materials found pretty much anywhere there is dirt, a team of Michigan State University researchers have developed a new thermoelectric material that transforms heat into electricity.
According to researchers led by Donald Morelli, a professor of chemical engineering and materials science, “What we’ve managed to do is synthesize some compounds that have the same composition as natural minerals.
“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.”
Morelli, who also directs MSU’s Center for Revolutionary Materials for Solid State Energy Conversion, says that because the vast majority of heat generated from, for example, a car engine, is lost through the tail pipe, many researchers have been trying to develop new thermoelectric materials to harness that waste. While some new, more efficient materials have been discovered, he says, many of those 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,” he says. “But that process costs a lot of money and takes a lot of time. Our method bypasses much of that.”
The MSU 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,” he says.
The researchers expect this discovery 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.
The research was published in the online journal Advanced Energy Materials.
The work is supported by a grant from the U.S. Department of Energy/Office of Science. The work is a partnership with the University of Michigan and UCLA. Other institutions involved with the MSU-based center are Northwestern University, the Ohio State University, Wayne State University and Oak Ridge National Laboratory.
For more information on the Center for Revolutionary Materials for Solid State Energy Conversion, visit www.egr.msu.edu/efrc/about-us.
— Tom Oswald and Donald Morelli via MSU Today and photos by G.L. Kohuth