Sponsors: DOE-NSF Partnership on Thermoelectrics. Bosch
Collaborators: University of South Florida, Bosch, Northrop Grumman
Students: Dr. Michael Barako, Maneeshika Madduri, Prof. Saniya LeBlanc (George Washington), Jena Barnes, Srilakshmi Lingamneni

A key to improving vehicle efficiency is recovering a fraction of the energy lost with the hot exhaust gases, and a promising strategy is to integrate thermoelectric generators with the exhaust system. Key challenges include the lack of interface materials connecting the thermoelectrics and the heat sinks. These interfaces must accommodate the massive fluctuations in thermomechanical strain between heat exchangers and the thermoelectric converters while providing providing excellent thermal and electrical contact. Additional problems include the need for high-temperature p and n type thermoelectric materials.

A Stanford-lead team with collaborators at Bosch and the University of South Florida is working on interface technologies, high-temperature thermoelectric conversion materials, and related advancements in metrology. Stanford focuses on the development (and metrology) of interface materials based on carbon nanotubes and metallic alloys to achieve thermal, mechanical, and electrical performance targets. A key benefit of this technology is the unique combination of mechanical compliance and high thermal conductivity, which is a key enabler for combustion systems. USF continues its groundbreaking work on high-temperature, scalable p- and n-type thermoelectrics (e.g., skutterudites and half-Heusler alloys). Bosch addresses system-level design requirements, including specific performance targets for automotive product markets.

This material is based upon work supported by the National Science Foundation under Grant No. 1048796. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

NSF-DOE Car
Thermoelectric modules are installed in the exhaust stream of an automobile to generate electricity from waste heat.
HighT Rig
High temperature measurement apparatus for infrared imaging
TE failure
Thermoelectric devices often fail due to stresses at interfaces, as seen through optical, infrared, and scanning electron microscopy
CNT-NF Bond
CNT film bonded to a substrate using Nanofoil