Abstract Strongly coupled electronic and thermal transport behavior in thermoelectric (TE) materials has limited their figure of merit (zT). Here we provide breakthrough in decoupling TE parameters in n-type (Hf0.6Zr0.4)NiSn0.99Sb0.01 half-Heusler (hH) alloys through multi-scale nanocomposite architecture comprising of tungsten nanoinclusions. The tungsten nanoparticles not only assist electron injection, thereby improving electrical conductivity, but also enhance the Seebeck coefficient through energy filtering effect. The microstructure comprises of disordered phases with varying size of microstructural features, which assists in effective scattering of heat-carrying phonons over diverse mean-free-path ranges. Cumulatively, these effects are shown to result in outstanding thermoelectric performance of zTmax ∼ 1.4 at 773 K and zTavg ∼ 0.93 between 300 and 973 K. Using this material, a TE generator is demonstrated, which exhibits high power density of 13.93 W cm−2 and conversion efficiency of 10.7% under ΔT = 674 K. The fundamental material design principle for TE nanocomposites demonstrated here can be generalized and extended to other TE systems.

中文翻译：

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多相 n 型半赫斯勒纳米复合材料中的声子电子传输解耦实现高效高温发电

摘要 热电 (TE) 材料中的强耦合电子和热传输行为限制了它们的品质因数 (zT)。在这里，我们通过包含钨纳米夹杂物的多尺度纳米复合结构在 n 型 (Hf0.6Zr0.4)NiSn0.99Sb0.01 半赫斯勒 (hH) 合金中解耦 TE 参数方面取得突破。钨纳米粒子不仅有助于电子注入，从而提高电导率，而且通过能量过滤作用增强塞贝克系数。微观结构由具有不同尺寸的微观结构特征的无序相组成，这有助于在不同的平均自由程范围内有效地散射载热声子。累积起来，这些效应显示出在 773 K 和 zTavg ∼ 0 时 zTmax ∼ 1.4 的出色热电性能。