原位析出共格/半共格纳米相p型方钴矿的快速制备与性能提升

Due to the fact that ZT value of the P-type skutterudites is far below n-type materials, and for real thermoelectric devices application, both n-type and p-type material is needed，in this project, we rapidly fabricate the p-type CoSb3 based skutterudite via melt spinning technique combined with high energy ball milling and spark plasma sintering (SPS). By carefully manipulating synthesis procedures, coherent/semi-coherent nanostructure by in-situ precipitation will be achieved in filled skutterudites. Furthermore, we will explore the influence of fabrication parameters on size and distribution of coherent/semi-coherent nanostructures and the corresponding thermoelectric properties of P-type skutterudites. The growth mechanism of coherent/semi-coherent nanostructure in p-type skutterudite will be clarified and the relationship between this nanostructure and the thermoelectric transport properties(especially for the Seebeck coefficient) will be demonstrated. This project is expected to achieve the controlled growth of in-situ nanostructure, synergistic enhancement mechanisms of the thermoelectric performance and largely raised ZT value in p-type CoSb3 based skutterudite. This work is a good example of how nanostructuring can be used to achieve the desirable electronic properties while maintaining a low thermal conductivity in skutterudite based thermoelectrics. The accomplishment of this project will boost the development of full skutterudite based thermoelectric devices.

针对p型方钴矿热电材料ZT值低于n型方钴矿材料的问题，本项目以p型方钴矿材料为研究对象，采用气氛熔体旋甩技术，结合高能球磨和放电等离子烧结（SPS)技术，快速制备具有原位析出共格/半共格纳米结构的p型方钴矿化合物，系统研究工艺参数对产物微结构的影响，探索原位析出纳米结构尺寸、形态和分布对材料热电性能的关联规律，把握能够改善热电性能的原位析出纳米相特征。项目预期将实现原位析出纳米结构的可控生长，掌握现有调制电热输运特性方法的"一体化"协同控制技术，大幅度提升p型方钴矿ZT值。项目研究成果对阐明p型方钴矿中共格/半共格纳米结构原位析出机制，揭示共格/半共格纳米结构对材料电声输运特性（特别是对Seebeck系数）的影响规律具有重要意义，为研制全方钴矿热电器件奠定基础。

针对p型方钴矿热电材料zT值低于n型方钴矿材料的问题，本项目以p型方钴矿材料为研究对象，采用气氛熔体旋甩技术，结合高能球磨和放电等离子烧结（SPS)技术，快速制备了具有原位析出共格/半共格纳米结构的p型方钴矿化合物；系统研究了工艺参数对产物微结构的影响；探明了原位析出纳米结构尺寸、形态和分布对材料热电性能的关联规律；最终实现了材料的Seebeck系数、电导率、热导率三个参数的解耦，大幅度提升了p型方钴矿基材料体系热电性能。为研制全方钴矿基热电器件提出了有效的理论基础和实验依据。同时，为其它材料体系的热电性能优化提供了新的思路和途径。