Li Wenjie, Poudel Bed, Kishore Ravi Anant, Nozariasbmarz Amin, Liu Na, Zhang Yu, Priya Shashank
Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA, 16802, USA.
National Renewable Energy Laboratory, 15013 Denver West Pkwy, Golden, CO, 80401, USA.
Adv Mater. 2023 May;35(20):e2210407. doi: 10.1002/adma.202210407. Epub 2023 Mar 31.
Waste-heat electricity generation using high-efficiency solid-state conversion technology can significantly decrease dependence on fossil fuels. Here, a synergistical optimization of layered half-Heusler (hH) materials and module to improve thermoelectric conversion efficiency is reported. This is realized by manufacturing multiple thermoelectric materials with major compositional variations and temperature-gradient-coupled carrier distribution by one-step spark plasma sintering. This strategy provides a solution to overcome the intrinsic concomitants of the conventional segmented architecture that only considers the matching of the figure of merit (zT) with the temperature gradient. The current design is dedicated to temperature-gradient-coupled resistivity and compatibility matching, optimum zT matching, and reducing contact resistance sources. By enhancing the quality factor of the materials by Sb-vapor-pressure-induced annealing, a superior zT of 1.47 at 973 K is achieved for (Nb, Hf)FeSb hH alloys. Along with the low-temperature high-zT hH alloys of (Nb, Ta, Ti, V)FeSb, the single stage layered hH modules are developed with efficiencies of ≈15.2% and ≈13.5% for the single-leg and unicouple thermoelectric modules, respectively, under ΔT of 670 K. Therefore, this work has a transformative impact on the design and development of next-generation thermoelectric generators for any thermoelectric material families.
利用高效固态转换技术进行废热发电可显著降低对化石燃料的依赖。在此，报告了一种对层状半赫斯勒（hH）材料和模块进行协同优化以提高热电转换效率的方法。这是通过一步放电等离子烧结制造具有主要成分变化和温度梯度耦合载流子分布的多种热电材料来实现的。该策略提供了一种解决方案，以克服传统分段结构仅考虑优值（zT）与温度梯度匹配的固有问题。当前的设计致力于温度梯度耦合电阻率和兼容性匹配、最佳zT匹配以及减少接触电阻源。通过锑蒸气压诱导退火提高材料的品质因数，（Nb, Hf）FeSb hH合金在973 K时实现了1.47的优异zT值。连同（Nb, Ta, Ti, V）FeSb的低温高zT hH合金，开发出了单级层状hH模块，在670 K的温差下，单腿热电模块和单偶热电模块的效率分别约为15.2%和13.5%。因此，这项工作对任何热电材料家族的下一代热电发电机的设计和开发都具有变革性影响。
