A TiAlCu Metallization for %26apos;n%26apos; Type Skutterudites with Improved Performance for High-Temperature Energy Harvesting Applications

作者：Rao Ashwin; Bosak Gregg; Joshi Binay; Keane Jennifer; Nally Luke; Peng Adam; Perera Susanthri; Waring Alfred; Poudel Bed

来源：Journal of Electronic Materials, 2017, 46(4): 2419-2431.

DOI：10.1007/s11664-017-5306-2

• Thermoelectric
• skutterudite
• metallization
• high temperature
• LabVIEW
• TE characterization
• testing

The choice of the appropriate metallizing layer for high-temperature thermoelectric (TE) materials is a tricky task and poses varied challenges to researchers. In this work, a n type TiAl metallizing layer (90% Ti with 10% Al by weight with a copper foil) is proposed for a skutterudite (SK) TE material coupled with a standard 'p type' SK base of with a 60:12:28% Fe:Ni:Cr metallizing layer. The n type and p type nanostructured SK powders are sintered at high temperatures and pressures in a DC hot press from which a TE device is assembled using diced, polished and property characterized TE legs (high figure of merit zT of 1.4 for n type and 1.2 for p type, respectively). The device is evaluated for functional degradation with repeated cycling to 500A degrees C hot side (HS) and 50A degrees C cold side (CS) temperatures in a specially designed high-vacuum test rig with key TE properties like peak power, open circuit voltage, and material internal resistance continuously recorded over each cycle. The device shows stable performance with < 7% drop in TE harvested power over similar to 2500 thermal cycles. With the industry benchmark for evaluating TE device performance being around 1000 thermal cycles (< 10% drop in TE power over time), the study indicates stable performance of the n type TiAl metallizing layer over the device lifetime.

• 出版日期2017-4