Nano-micro-porous skutterudites with 100% enhancement in ZT for high performance thermoelectricity

Authors

Atta U. Khan, National Institute for Materials Science, Japan
Kazuaki Kobayashi, National Institute for Materials Science, Japan
Dai-Ming Tang, National Institute for Materials Science, Japan
Yusuke Yamauchi, National Institute for Materials Science, JapanFollow
Kotone Hasegawa, National Institute for Materials Science, Japan
Masanori Mitome, National Institute for Materials Science, Japan
Yanming Xue, National Institute for Materials Science, Japan
Baozhen Jiang, National Institute for Materials Science, Japan
Koichi Tsuchiya, University of Tsukuba, National Institute For Materials Science, Japan
Dmitri Golberg, University of Tsukuba, National Institute For Materials Science, Japan
Yoshio Bando, National Institute for Materials Science, JapanFollow
Takao Mori, University of Tsukuba, National Institute For Materials Science, Japan

RIS ID

121419

Publication Details

Khan, A. U., Kobayashi, K., Tang, D., Yamauchi, Y., Hasegawa, K., Mitome, M., Xue, Y., Jiang, B., Tsuchiya, K., Golberg, D., Bando, Y. & Mori, T. (2017). Nano-micro-porous skutterudites with 100% enhancement in ZT for high performance thermoelectricity. Nano Energy, 31 152-159.

Abstract

Increasing energy demands require new materials, e.g., thermoelectrics, for efficient energy conversion of fossil fuels. However, their low figure of merit (ZT) limits widespread applications. Nanostructuring has been an effective way of lowering the thermal conductivity. However, grain growth at elevated temperature is still a big concern, for otherwise expected to be long-lasting thermoelectric generators. Here, we report a porous architecture containing nano- to micrometer size irregularly shaped and randomly oriented pores, scattering a wide spectrum of phonons without employing the conventional rattling phenomenon. Lattice thermal conductivity reaches the phonon glass limit. This design yields > 100% enhancement in ZT, as compared to the pristine sample. An unprecedented and very promising ZT of 1.6 is obtained for Co23.4Sb69.1Si1.5Te6.0 alloy, by far the highest ZT ever reported for un-filled skutterudites, with further benefits, i.e. rare-earth-free and improved oxidation resistance enabling simple processing.