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Practical thermoelectric material that shows stable performance at high temperatures in air is discovered — Oxide thermoelectric material with good reproducibility and high performance at a practical level —

Posted Date:
Laboratory of Functional Thin Film Materials

POINT

  • It was discovered that Ba1/3CoO2 shows figure of merit ZT = 0.55 at 600 °C in air.
  • High-ZT comparable to practical non-oxide thermoelectric materials.
  • High performance with good reproducibility at high temperatures in air.

The research group of Professor Hiromichi Ohta of Research Institute for Electronic Science, Hokkaido University, and Dr. Akihiro Tsuruta, Senior Researcher of AIST found that practical thermoelectric material that exhibits stable performance at 600 C in air. Thermoelectric conversion is attracting attention as a technology for recycling waste heat discharged from factories and automobiles. Metallic chalcogenides including practical PbTe are thermally and chemically unstable, and toxic, therefore, the application is still limited. Compared to PbTe, oxides are expected to be a thermoelectric material that can be used at high temperatures because they basically do not oxidize even at high temperatures. In Japan, oxide-based thermoelectric materials have been energetically studied for about 30 years. So far, some oxide thermoelectric materials with a high ZT have been proposed, but they have not been put into practical use due to their low reproducibility. In 2020, the research group discovered that Ba1/3CoO2 showed a high ZT ~ 0.11 at room temperature (https://www.hokudai.ac.jp/news/2020/11/post-747.html). In this study, the research group investigated the stability of Ba1/3CoO2 epitaxial thin film at high temperatures in air and measured the thermoelectric properties within this stable temperature range. As a result, it was discovered that Ba1/3CoO2 shows ZT ~ 0.55 in air at 600 ℃ in order to clarify the reproducible high-temperature thermoelectric characteristics of Ba1/3CoO2. Thus, a practical thermoelectric material that exhibits high performance with good reproducibility at high temperatures in air has finally been realized.

The results of this research were published in ACS Applied Materials & Interfaces (Open Access) on July 12, 2022 (Tuesday).

Xi Zhang#, Yuqiao Zhang#*, Liao Wu, Akihiro Tsuruta, Masashi Mikami, Hai Jun Cho, and Hiromichi Ohta*, “Ba1/3CoO2: A Thermoelectric Oxide Showing a Reliable ZT of ∼0.55 at 600 °C in Air”, ACS Appl. Mater. Interfaces XX, XXXX (2022). (July 12, 2022) (DOI: 10.1021/acsami.2c08555) OPEN ACCESS

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