Kanas Nikola, Bjørk Rasmus, Wells Kristin Høydalsvik, Schuler Raphael, Einarsrud Mari-Ann, Pryds Nini, Wiik Kjell
Department of Materials Science and Engineering, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway.
Department of Energy Conversion and Storage, Technical University of Denmark, 2800 Kongens Lyngby, Denmark.
ACS Omega. 2020 Dec 28;6(1):197-205. doi: 10.1021/acsomega.0c04134. eCollection 2021 Jan 12.
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 CaCo O (CCO, p-type) and CaMnO/CaMnO (CMO, n-type). Different module (unicouple) designs were studied to obtain a thorough understanding of the role of the formed hybrid p-n junction of CaCoMnO (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/cm (7.2 mW) at Δ ∼ 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.
全氧化物热电模块目前面临的挑战是，由于热端金属氧化物界面的不稳定性，它们在高温下的耐久性较差。这项工作阐述了一种基于混合 p-n 结的新型模块概念，该模块通过对 CaCoO（CCO，p 型）和 CaMnO/CaMnO（CMO，n 型）进行火花等离子体共烧结一步制成。研究了不同的模块（单偶）设计，以深入了解在模块性能中，在 p-n 结（>700°C）处形成的 CaCoMnO（CCMO，p 型）与富 Co 氧化物相（p 型）的混合 p-n 结所起的作用。由于混合 p-n 结具有独特的电学特性，即在高温（>700°C）下具有足够的导电性，而在中低温下不导电，因此观察到模块性能因这种 p-n 结的形成而随时间增强。在 900°C 热端等温保持 2 天后，在 Δ ∼ 650°C 时，模块设计的改变导致功率密度从 12.4（3.1）变化到 28.9 mW/cm²（7.2 mW）。这一新概念为制造易于加工、廉价且高性能的高温模块提供了一种简便方法。
