Shenzhen Key Laboratory of Thermoelectric Materials, Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China.
Department of Materials Science and Engineering, National University of Singapore, Singapore 117575, Singapore.
Science. 2021 Feb 19;371(6531):830-834. doi: 10.1126/science.abe1292.
Thermoelectric technology generates electricity from waste heat, but one bottleneck for wider use is the performance of thermoelectric materials. Manipulating the configurational entropy of a material by introducing different atomic species can tune phase composition and extend the performance optimization space. We enhanced the figure of merit () value to 1.8 at 900 kelvin in an n-type PbSe-based high-entropy material formed by entropy-driven structural stabilization. The largely distorted lattices in this high-entropy system caused unusual shear strains, which provided strong phonon scattering to largely lower lattice thermal conductivity. The thermoelectric conversion efficiency was 12.3% at temperature difference Δ = 507 kelvin, for the fabricated segmented module based on this n-type high-entropy material. Our demonstration provides a paradigm to improve thermoelectric performance for high-entropy thermoelectric materials through entropy engineering.
热能技术可从废热中产生电能，但更广泛应用的一个瓶颈是热电材料的性能。通过引入不同的原子种类来操纵材料的构象熵，可以调整相组成并扩展性能优化空间。我们通过熵驱动的结构稳定化，在基于 PbSe 的 n 型高熵材料中，将（品质因数）值提高到了 900 开尔文时的 1.8。在这个高熵系统中，晶格发生了很大的扭曲，产生了异常的剪切应变，这对声子散射提供了很强的散射，从而大大降低了晶格热导率。基于这种 n 型高熵材料的分段模块，在温差Δ=507 开尔文时，其热电转换效率为 12.3%。我们的研究结果为通过熵工程提高高熵热电材料的热电性能提供了范例。
