Harvesting waste energy using thermoelectric (TE) principles is a key technology that increases overall power conversion and efficiency from combustion-based energy generation systems. However, design restrictions of commercially available thermoelectric devices and toxicity of commercial thermoelectric materials currently limit large-scale deployment. Additive and multilayered design and manufacturing of thermoelectric modules are a potential pathway to overcome current design restrictions as it enables to implement the device directly to the engineering structures with direct access to waste heat. Plasma spray is the chosen technology in this work to fabricate such patterned and layered TE devices, using as p-type Ca2Co2O5 and the n-type material TiO2-x. The optimization of thermoelectric leg geometry results in a maximum power density output of 1.9 × 10−4 W/cm2 per couple and efficiency of 1.1% at 750 K. An important aspect of this TE device design is that it allows direct p-n contact, whereas the proportionality between p-n contact area and power output is demonstrated. A correlation between the coating thickness and nonlinear behavior of the thermoelectric voltage is also discussed, which is associated with the anisotropy degree of the n-type coating.

中文翻译：

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等离子喷涂制备全氧化物二维层状热电器件的优化

使用热电 (TE) 原理收集废能是一项关键技术，可提高基于燃烧的能源发电系统的整体功率转换和效率。然而，商用热电器件的设计限制和商用热电材料的毒性目前限制了大规模部署。热电模块的增材和多层设计和制造是克服当前设计限制的潜在途径，因为它能够将设备直接实施到工程结构中，并直接获得废热。等离子喷涂是这项工作中选择的技术来制造这种图案化和分层的 TE 器件，使用 p 型 Ca2Co2O5 和 n 型材料 TiO2-x。热电腿几何结构的优化导致每对最大功率密度输出为 1.9 × 10−4 W/cm2，在 750 K 时效率为 1.1%。这种 TE 器件设计的一个重要方面是它允许直接 pn 接触，而证明了 pn 接触面积和功率输出之间的比例。还讨论了涂层厚度与热电电压非线性行为之间的相关性，这与 n 型涂层的各向异性程度有关。