SBIR-STTR Award

The objective of this proposal is to develop and implement methodologies for new bulk thermoelectric materials that incorporate nanostructural elements to significantly increase the thermoelectric figure of merit, ZT, by way of phonon boundary scattering providing enhanced fuel economy via waste-heat to electrical energy conversion as well as provide stand-alone power from either intentional fuel sources or naturally occurring heat harvesting circumstances. Three primary methods will be used to develop nanostructures within a target thermoelectric alloy (AgPbmSbTe2+m) with the goal of developing a commercially realizable bulk material methodology resulting in high ZT thermoelectric devices. The unique cubic AgPbmSbTe2+m (LAST) structural identity can be exploited to produce nanostructural components that will act as phonon scattering sites within the bulk material. Tellurex's continuing work on the LAST system indicates that structural grain size reduction may be brought to nanoscale through rapid quenching and advanced mechanical powder processing techniques. A scaled sintering regimen will also be developed and employed to induce nanoscale boundary growth providing phonon boundary scattering. These processes will be used singularly and in combined strategies to determine the method resulting in the highest ZT and provide the focus for Phase II and Phase III development

The objective of this proposal is to leverage the exceptional results and learning from the Phase I program to develop and implement bulk material processes to produce thermoelectric materials on a pilot plant scale and make thermoelectric component pellets that are fabricated into complete, testable, multi-couple modules with significantly increased thermoelectric figure of merit, ZT. The phonon scattering provided by the process as proven in the Phase I program manifests high ZT thermoelectric material, providing for future enhanced fuel economy via waste-heat to electrical energy conversion as well as provide quiet, efficient standalone power from dedicated intentional fuel sources or naturally occurring heat harvesting circumstances such as internal combustion engines. Verified Phase I methodologies of bulk material quick processing that include rapid quenching, advanced powder preparation techniques and controlled nano-structure sintering will be scaled-up and brought to precision control. Combined with intrinsic boundary/transition layer fusion and powder characterization, it is proposed to develop the capability to make large compacts of the target AgPbmSnmSbTe11+m (LASTT) alloy that will be fabricated into pellets for multicouple modules for real world use. The proposed highly adaptable process will also be applicable for high volume AgPbmSbTe2+m (LAST) alloy production of module ready pellets.

Keywords:
Thermoelectric, High ZT, Bulk Materials, Nanostructures, Phonon Engineering, Power Generation, Energy Harvesting, Press & Sinter