原位生长碳管复合热电材料的制备及其器件

With the ability to achieve mutual conversion between thermal and electrical energy, as well as the advantages of small volume, no-noise, high reliability, et al, thermoelectric materials have been applied in the field of aerospace engineering, national defense, semiconductor refrigeration and waste heat power generation. The research of thermoelectric materials have made considerable strides in recent years, however, the research of the thermoelectric device can not satisfy the development of materials, which can be attributed to the lack of stable thermoelectric properties, batch production, and excellent mechanical property. Generally, multi-element doping, solid solution method, et al, are employed to the enhance ZT value, which makes it difficult to prepare thermoelectric materials with high ZT value in high field. As a result, high-performance thermoelectric materials develop slowly...In view of the above questions, this project is proposed to enhance the thermoelectric and mechanical properties by in-situ wrapping magnetic nanoparticles, which is employed as catalyst, in the surface of thermoelectric particles (CoSb3, SnSe, et al). Besides, carbon nanotube is in-situ synthesized by chemical vapor deposition method, and heterogenous interface is formed at grain boundaries. Meanwhile, magnetic nanoparticles embedded in thermoelectric materials will act as multiple scattering centres of the electrons, which can realize energy filtering effect, enhance phonon scattering, and consequently decrease the thermal conductivity of the lattice. The thermoelectric and mechanical properties can be enhanced simultaneously, and it is favorable to expedite the development and application of high-performance thermoelectric materials.

热电材料可以实现热能和电能相互转换，具有器件体积小、可靠性高、无噪音等优点，可用于废热发电和制冷，已在航天、国防、半导体制冷等领域获得应用。热电材料的研究已经取得了长足的进步，但热电器件研究远远低于材料的发展，这是因为制备器件要求材料具有热电性能稳定、可批量制备、力学性能满足可加工的要求。然而，通常采用多元素掺杂、固溶等方式制备高ZT值热电材料，导致批量制备高ZT值热电材料存在困难，所以高性能热电器件发展缓慢。. 针对上述问题，本项目提出在CoSb3、SnSe等颗粒表面原位包裹磁性纳米粒子作为催化剂，采用CVD合成碳管解决CNTs在基体中难以分散的问题，在晶界处构筑异质界面，同时利用催化剂磁性纳米粒子形成电子多重散射中心，实现能量过滤效应，增强声子散射，降低声子热导率，实现热电性能和力学性能协同提高，制备出高性能热电器件，加快推动高性能热电器件的发展和应用进程。

热电材料可以实现热能和电能相互转换，具有器件体积小、可靠性高、无噪音等优点，可用于废热发电和制冷，已在航天、国防、半导体制冷等领域获得应用。热电材料的研究已经取得了长足的进步，但热电器件研究远远低于材料的发展，这是因为制备器件要求材料具有热电性能稳定、可批量制备、力学性能满足可加工的要求。然而，通常采用多元素掺杂、固溶等方式制备高ZT值热电材料，导致批量制备高ZT值热电材料存在困难，所以高性能热电器件发展缓慢。.本项目采用化学气相沉积技术成功地在GeTe、SiGe、ZnO和钛酸锶颗粒表面原位生长了CNTs，解决了目前CNTs在基体材料中难以均匀分散的问题，并结合放电等离子体快速烧结工艺成功地制备了具有多尺度结构的热电块体材料。本项目系统研究了CNTs合成工艺对CNTs含量与分布、样品热电性能和力学性能的影响规律，揭示了引入的CNTs和构建的多尺度微结构对热电输运和电声相互作用规律，建立了微结构设计与可控制备技术，实现了电和热输运性能的协同调控，成功制备出高性能热电材料。在上述工作基础上，本项目进一步拓展了热电材料体系研究，包括制备了低维纳米材料复合热电材料和CNTs基热电纤维，获得了具有良好热电性能的柔性器件，为制备其它高性能热电材料探索了一条可行的新途径。在本项目的资助下，在Energy & Environmental Science、 Nature Communications、Advanced Energy Materials、Journal of Advanced Ceramics等高水平期刊上发表研究论文22篇，申请国家发明专利2项，其中1项已授权，同时培养研究生6名。