Time-enhanced performance of oxide thermoelectric modules based on a hybrid p-n junction
Kanas, Nikola; Bjørk, Rasmus; Wells, Kristin Høydalsvik; Schuler, Raphael; Einarsrud, Mari-Ann; Pryds, Nini; Wiik, Kjell
Peer reviewed, Journal article
Published version
Åpne
Permanent lenke
https://hdl.handle.net/11250/2983626Utgivelsesdato
2021Metadata
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- Institutt for materialteknologi [2503]
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Sammendrag
The present challenge with all-oxide thermoelectric modules is their poor durability at high temperatures caused by the instability of the metal-oxide interfaces at the hot side. This work explains a new module concept based on a hybrid p–n junction, fabricated in one step by spark plasma co-sintering of Ca3Co4–xO9+δ (CCO, p-type) and CaMnO3−δ/CaMn2O4 (CMO, n-type). Different module (unicouple) designs were studied to obtain a thorough understanding of the role of the in situ formed hybrid p–n junction of Ca3CoMnO6 (CCMO, p-type) and Co-oxide rich phases (p-type) at the p–n junction (>700 °C) in the module performance. A time-enhanced performance of the modules attributed to this p–n junction formation was observed due to the unique electrical properties of the hybrid p–n junction being sufficiently conductive at high temperatures (>700 °C) and nonconductive at moderate and low temperatures. The alteration of module design resulted in a variation of the power density from 12.4 (3.1) to 28.9 mW/cm2 (7.2 mW) at ΔT ∼ 650 °C after 2 days of isothermal hold (900 °C hot side). This new concept provides a facile method for the fabrication of easily processable, cheap, and high-performance high-temperature modules.