The objective of this proposal is to develop high efficiency thermoelectric composites. We propose a new hierarchical multiscale strategy to develop high efficiency thermoelectric composites that build upon atomistic-nano-continuum computation guided material design; interfacial modification techniques; bulk functional gradient approaches; and nano-to-continuum characterization methodologies that are being developed at the University of Washington and at the General Motors R&D Center. We will apply these methodologies to solve critical problems of designing and developing high efficiency thermoelectric composites. There are three main tasks: 1. determining the optimized atomistic composition, molecular surface modification, and macroscopic morphology with first-principles, perturbation theory, and continuum modeling; 2. synthesizing bulk thermoelectric composites containing nano-scale grain with surface modifications and macroscopic functional gradients; and 3. characterizing electron and phonon transport from the molecular to the macro-scale. These tasks extend existing modeling and experimental capabilities, provide new understanding of interfacial and functional gradient electron and phonon scattering mechanisms, and directly interface with industrial development of thermoelectric waste heat recovery technology for improved fuel economy.
Hierarchical multiscale composites are chosen for their potential to have the greatest impact on understanding nano-to-macro electron and phonon transport on thermoelectric properties of materials as well as their industrial development. Connecting fundamental electronic structure studies of alloys and interfaces at the atomistic scale and bridging this to continuum modeling for new materials design; coupling with materials synthesis and characterization for validation; and direct incorporation in industrial usage is a potentially transformative concept in materials science and engineering. It offers the promise to move beyond the existing trial-and-error approaches, and the combined talents of the academic-industrial collaboration with GOALI are uniquely positioned to meet this challenge. The long-term impact of this project is a reduction in global energy demands through increased efficiency and reduction in U.S. dependency on foreign energy sources without compromising safety in the transportation industry, as well as many other industrial sectors. GOALI?s direct industrial partnership accelerates the assimilation of basic science research into industrial practice. Besides the indicated long-term societal benefits, a key component of this proposal is the education of students and postdocs for the twenty-first century workforce and efforts to increase diversity in science and engineering, as well as outreach to K12 schools. GOALI also involves students directly in connecting science to industrial technology development.
