多尺度结构CoSb3基复合材料异质界面设计构筑与性能调控

热电材料在工业废热发电等领域具有广阔的应用前景。然而热电材料较低ZT值是制约制其应用的主要因素。低维化和纳米化是实现电、声输运特性的协同调控从而优化热电性能，是当前热电材料领域的一个重要研究方向。由于低维纳米热电材料短期内要实现大规模商业化应用还存在很多问题。如何将低维热电材料中的结构特征和物理效应复制到块状热电材料中，以加快热电转换技术大规模商业化应用的进程，是当前高效热电材料研究的前沿热点。本研究提出了采用超低温冷冻研磨技术合成高质量CoSb3基纳米热电粉体，然后引入不同物理特性纳米粒子构筑异质界面层降低热导率，在烧结过程中通过温度分离制备出具有多尺度微纳结构提高其载流子输运能力，重点研究异质界面层与多尺度微结构对热电性能的影响机制，预期获得高性能CoSb3基热电材料，为其它热电材料的制备提供借鉴。

Thermalelectric(TE) materials can be used to convert waste heat to electricity,thus thermoelectric technology has therefore arouse worldwide interest in many fields. Low-dimensional and nanosized structure is thought to enhance properties of TE materials, which attract a great deal of attentions. However, it is not practical for large-scale commercial use for these low-dimensional TE materials. How to produce the bulk TE materials with nano-structure and excellent physics properties of low-dimensional TE materials is the hotspot research. In this project, a novel method, cryogenic grinding, for the preparation of CoSb3 based nano-sized powders are given. The nano-sized particles with different physical properties will be introduced to construct hetero-interface of bulk materials for reducing thermal conductivity, and the hierachical-structured bulk materials with high carrier concentration can be prepared by temperature separation during sintering process. The effect of hetero-interface and hierachical-structure on properties of bulk materials will investigated in detail, which will provide some suggestions for preparing other TE materials.