热电材料可实现热能与电能相互转换，在温差发电及半导体制冷领域具有广阔的应用前景。然而，热电材料转换效率较低和服役性能较差限制了其在工业上的应用。本项目抓住Half-Heusler合金的高热导率为制约其热电性能进一步提升的关键，拟通过高熵合金设计思想，以ZrNiSn合金为高熵热电合金母版，在Zr、Ni和Sn位进行重替代，形成多组元高熵热电材料。基于伪二元相图、密度泛函第一性原理和玻尔兹曼输运方程计算，优化出最优合金成分范围。采用同步辐射原位PDF、SR-μXRD和TEM等方法定量表征合金的微结构演化，揭示热电材料“合金成分-制备工艺-微结构-热电性能-机械性能”间关联响应机理。巧妙利用高熵合金产生的四大核心效应，通过全尺度微观结构设计抑制晶格热导率，在保留较高功率因子的同时，有效降低热导率，有望同时实现热电和机械性能的大幅提升，为中高温热电材料产业化应用提供更多可能。

Thermoelectric materials, which are capable of direct conversion between electrical energy and thermal energy, have received extensive attention recently for their great potential applications in the fields of power generation and semiconductor refrigeration. However, the low energy conversion efficiency and poor service performance of thermoelectric materials limit its commercial application. As we know, the key to further improve the thermoelectric properties of Half-Heusler alloy is to depress its high thermal conductivity compared to other traditional thermoelectric materials. In this proposal, based on the design concepts of high-entropy alloys, we choose ZrNiSn as the master template, and heavy substituting of doping Zr, Ni and Sn sites by isoelectronic or different valence electronic elelments to form multi-component high-entropy Half-Heusler thermoelectric alloys. The Calphad pseudo-binary phase diagram, first principle, Boltzmann transport calculations are used to choose substituting and doping elements and optimize their contents, and design the best composition ranges of high-entropy Half-Heusler thermoelectric alloys. The microstructural evolution of high-entropy Half-Heusler thermoelectric alloys is quantitatively characterized by high-energy synchrotron radiation in-situ PDF, SR-μXRD and TEM. As a result, a relationship between the alloy composition, the preparation processes, the microstructures, the thermoelectric properties and the mechanical properties will be established. Rooted in the four core effects of high-entropy alloys properly, the lattice thermal conductivity of high-entropy Half-Heusler thermoelectric alloys can be significantly decreased by all-scale hierarchically structured design. Consequently, it is promising that the thermoelectric properties and mechanical properties of high-entropy Half-Heusler thermoelectric alloys can be markedly enhanced simultaneously by coupling the high power factor and low lattice thermal conductivity. This project will provide more opportunities for the industrial applications of morderate and high-temperature thermoelectric materials.