High-entropy-stabilized chalcogenides with high thermoelectric performance
High-entropy-stabilized chalcogenides with high thermoelectric performance
复制标题
具有高热电性能的高熵稳定硫属化物
DOI：
10.1126/science.abe1292
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发表时间：
2021-02-19
期刊：
影响因子：
56.9
通讯作者：
He, Jiaqing
中科院分区：
文献类型：
--
作者：
Jiang, Binbin;Yu, Yong;He, Jiaqing
扭曲的热物性热电装置可以将余热转化为电能，为提高能源效率提供了一条途径。蒋等人利用熵工程合成了一种具有诱人热电性能的单相高熵合金。通过增加合金中元素的数量，所产生的无序有助于稳定，防止分解成多个相。无序和扭曲的晶格在保持电学性能的同时抑制了热传输，从而提高了材料的热转换效率。科学，本期第830页高熵合金中的晶格扭曲降低了导热系数并改善了热电性能。热电技术利用余热发电，但推广使用的一个瓶颈是热电材料的性能。通过引入不同的原子物种来控制材料的构型熵，可以调整相组成，扩展性能优化空间。我们将n型PbSe基高熵材料在900开尔文时的优值因子(ZT)提高到1.8，这种材料是由熵驱动的结构稳定化形成的。在这个高熵系统中，严重扭曲的晶格产生了异常的剪切应变，这提供了很强的声子散射，从而大大降低了晶格的热导率。在温差ΔT=507Kelvin时，基于该n型高熵材料制作的分段式组件的热电转换效率为12.3%。我们的论证为通过熵工程改善高熵热电材料的热电性能提供了一个范例。
Distorted thermal properties Thermoelectric devices can convert waste heat into electricity, providing one path for improving energy efficiency. Jiang et al. leveraged entropy engineering to synthesize a single-phase high-entropy alloy with attractive thermoelectric properties. By increasing the number of elements in the alloy, the resulting disorder helps to stabilize against breakdown into multiple phases. The disordered and distorted crystal lattice suppresses thermal transport while maintaining the electrical properties, which boosts the heat-conversion efficiency of the material. Science, this issue p. 830 Lattice distortions in a high-entropy alloy reduce thermal conductivity and improve thermoelectric properties. 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 (zT) 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 ΔT = 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.