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https://hdl.handle.net/2115/86588

Ba1/3CoO2 : A Thermoelectric Oxide Showing a Reliable ZT of similar to 0.55 at 600 degrees C in Air

英語

figure of merit thermal stability

2022-07-27

American Chemical Society

ACS applied materials & interfaces

14(29)

33355-33360

Thermoelectric energy conversion technology has attracted attention as an energy harvesting technology that converts waste heat into electricity by means of the Seebeck effect. Oxide-based thermoelectric materials that show a high figure of merit are promising because of their good chemical and thermal stability as well as their harmless nature compared to chalcogenide-based state-of-the-art thermoelectric materials. Although several high-ZT thermoelectric oxides (ZT > 1) have been reported thus far, the reliability is low due to a lack of careful observation of their stability at elevated temperatures. Here, we show a reliable high-ZT thermoelectric oxide, Ba1/3CoO2. We fabricated Ba1/3CoO2 epitaxial films by the reactive solid-phase epitaxy method (Na3/4CoO2) followed by ion exchange (Na+ -> Ba2+) treatment and performed thermal annealing of the film at high temperatures and structural and electrical measurements. The crystal structure and electrical resistivity of the Ba1/3CoO2 epitaxial films were found to be maintained up to 600 degrees C. The power factor gradually increased to similar to 1.2 mW m(-1) K-2 and the thermal conductivity gradually decreased to similar to 1.9 W m(-1) K-1 with increasing temperature up to 600 degrees C. Consequently, the ZT reached similar to 0.55 at 600 degrees C in air.

学術雑誌論文

Version of Record

1944-8244