Commercializing new low-cost thermoelectric materials

July 7, 2014

Thermoelectric leaders at Alphabet Energy and Michigan State University have entered a key partnership for the exclusive commercialization of new materials that will help lower costs for converting heat to electricity. The announcement was made July 7 during the 2014 International Conference of Thermoelectrics in Nashville, Tenn.

The research that advanced this new thermoelectric material was led by Don Morelli, a professor of materials science in the MSU College of Engineering.Research by Don Morelli that led to a collaboration with Alphabet Energy on a new thermoelectric material is featured in the journal, "Advanced Energy Materials."

“In our search for efficient, abundant, and nontoxic thermoelectric materials, we were led to the tetrahedrites, a family of compounds of commonly occurring elements, by theoretical calculations of their properties," Morelli explained. "The fact that they are naturally-occurring minerals is an added bonus – one can either synthesize them in the lab or use the natural mineral itself as a source thermoelectric material. The compounds are especially interesting because they combine very low thermal conductivity with unusually good electronic properties."

Alphabet’s thermoelectrics materials team, comprised of several leading industry experts, quickly recognized the value of tetrahedrite in complementing its existing silicon-based technology innovations.

Morelli, who led the research that was published in the journal, Advanced Energy Materials, said the process is only the first step in creating a low-cost, widespread technology for converting heat to electricity. "We are excited to work with Alphabet Energy because they have the resources, knowledge, and experience to take these materials from the laboratory to the marketplace."

Thermoelectric materials convert any waste heat source into electricity. While they have been studied for decades, only a few have reached commercial applications because of their low efficiency, high cost, and use of rare elements.

Alphabet’s continued advances with highly efficient silicon nanowire-based thermoelectrics also reached key milestones recently with the issuance of two patents for the scalable manufacturing of these nanomaterials to use as thermoelectrics. A single nanowire is the width of 1/1000 of a human hair, but dozens of kilograms of materials are needed for a large-scale industrial thermoelectric generator. Alphabet’s materials inventions are the first that allow the bulk incorporation of nanowires into macroscopic materials, paving the way for nanowire-based thermoelectric devices.

“These new materials play a key role in our forthcoming products,” said Alphabet Founder and CEO, Matthew L. Scullin. “Our goal at Alphabet is to continually deliver value to our customers by identifying and inventing the best thermoelectric materials for waste-heat recovery that can improve efficiency while reducing costs.”

Alphabet Energy is based in Hayward, Calif.