Abstract Thermoelectric generators (TEGs) with improved conversion efficiency are in great need for low-grade heat recovery. Existing studies primarily optimize the dimensionless figure of merit (ZT) of thermoelectric (TE) materials to improve TEG efficiency. However, TE material with a high ZT cannot guarantee that associated TEG has an optimal performance in practical conditions. To solve this problem, an experiment-verified model is proposed considering the effective temperature difference, optimal matching resistance and contact effect. Sensitivity analysis has been conducted to inversely identify the optimization direction of TE materials at the device level. The impacts of the key physical properties on TEG performance are systematically studied under typical operating conditions. The study results show that reducing lattice thermal conductivity is of more priority than increasing the power factor for improving TEG performance. For power factor improvements of TE materials, Seebeck coefficient optimization is found to be more important than electrical conductivity increase. Besides, the impacts of operating conditions on optimizing TE materials are also investigated. Finally, an optimization process to improve the generation performance of TE materials is proposed, which opens up a new way to lead the development of TE materials from the device and application level. The study results are helpful to effectively improve the power generation performance of TEG through the proposed optimized method of TE materials.

中文翻译：

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从器件层面对热电材料进行逆优化研究

摘要 具有改进转换效率的热电发电机 (TEG) 非常需要低品位热回收。现有研究主要优化热电 (TE) 材料的无量纲品质因数 (ZT) 以提高 TEG 效率。然而，具有高 ZT 的 TE 材料不能保证相关的 TEG 在实际条件下具有最佳性能。针对这一问题，提出了一种综合考虑有效温差、最佳匹配电阻和接触效应的实验验证模型。已经进行了灵敏度分析，以在器件级别反向识别 TE 材料的优化方向。在典型的操作条件下系统地研究了关键物理特性对 TEG 性能的影响。研究结果表明，对于提高 TEG 性能，降低晶格热导率比提高功率因数更重要。对于 TE 材料的功率因数改进，发现塞贝克系数优化比增加电导率更重要。此外，还研究了操作条件对优化热电材料的影响。最后，提出了提高热电材料发电性能的优化流程，为从器件和应用层面引领热电材料发展开辟了新途径。研究结果有助于通过提出的TE材料优化方法有效提高TEG的发电性能。对于 TE 材料的功率因数改进，发现塞贝克系数优化比增加电导率更重要。此外，还研究了操作条件对优化热电材料的影响。最后，提出了提高热电材料发电性能的优化流程，为从器件和应用层面引领热电材料发展开辟了新途径。研究结果有助于通过提出的TE材料优化方法有效提高TEG的发电性能。对于 TE 材料的功率因数改进，发现塞贝克系数优化比增加电导率更重要。此外，还研究了操作条件对优化热电材料的影响。最后，提出了提高热电材料发电性能的优化流程，为从器件和应用层面引领热电材料发展开辟了新途径。研究结果有助于通过提出的TE材料优化方法有效提高TEG的发电性能。提出了一种提高热电材料发电性能的优化流程，为从器件和应用层面引领热电材料发展开辟了新途径。研究结果有助于通过提出的TE材料优化方法有效提高TEG的发电性能。提出了一种提高热电材料发电性能的优化流程，为从器件和应用层面引领热电材料发展开辟了新途径。研究结果有助于通过提出的TE材料优化方法有效提高TEG的发电性能。