Bi2Te3基柔性热电材料的3D打印低成本可控制备与结构调控特性研究

Bismuth telluride based thermoelectric materials is one of the new energy thermoelectric power generation the most research value of thermoelectric materials, the use of 3D printing technology for preparation of thermoelectric materials according to the external dimensions of thermoelectric materials heat source with high efficiency and low cost preparation of the perfect fit, this technique is very suitable for promotion in the field of new energy. The thermoelectric material parameters of decoupling difficult, ZT value problem of promotion of 3D printing technology to print the 3D challenge, the regulation of structure and the figure of merit association mechanism of scientific subject, characterized by laboratory testing method of material preparation and laboratory study on the influence of the preparation of Bi2Te3 powder on the structure and regulation of power excellent value, research on 3D printing parameters regulating value of influence on the thermoelectric, establishment of 3D printing structure regulation and ZT value relevance model. The design principle and the theoretical basis of the project is expected to establish a bismuth telluride based thermoelectric material 3D printing, foundation and guarantee of research results as 3D printing technology applied to thermoelectric material production field, has significant academic value and scientific significance in improving the structure and properties of 3D print control methods, ZT value promotion mechanism of multiple research field.

Bi2Te3基热电材料是废热温差发电应用中最具研究价值的室温热电材料之一。利用3D打印技术能够根据热源外部尺寸高效、低成本制备形状贴合的热电材料，有利于热能的转换利用，十分适合推广于新能源领域。针对热电材料参数间解耦困难，热电优值提升所面临的瓶颈对3D打印技术提出的挑战，以3D打印结构调控与热电优值关联机制为科学问题对象，采用实验室材料制备及实验室表征测试方法，研究Bi2Te3基粉体制备对结构调控及热电优值的影响规律，研究3D打印参数结构调控对热电优值影响规律，建立3D打印结构调控与热电优值关联模型。项目预期将建立Bi2Te3基热电材料3D打印的设计原则和理论依据，研究成果作为3D打印技术推广到热电材料生产领域的基础和保障，在提升3D打印结构及性能调控方法、热电优值提升机制等多个研究领域具有显著的学术价值和科学意义。

热电材料是一种能实现热能和电能直接转化的新型功能材料，在热电制冷和温差发电领域有广泛的应用前景。但目前仅有Bi2Te3等少数成熟的商业热电材料种类，不能满足广温域热源的应用需求。且传统成型方法难以制备复杂形状的块体，影响了非平面热源应用中的热传递效率。本文针对高效率、广温域的热电材料设计与成型技术需求，围绕室温、中、高温热电材料性能及制备工艺优化开展研究。.①针对单晶中温热电材料SnSe制备工艺复杂、机械性能差的问题，研究多晶SnSe的热电性能优化工艺。结果表明，Na、Ag共掺热电可以实现热导率、载流子浓度协同调控。其中，Na掺杂有效提高样品的载流子浓度，Na、Ag样品中形成的不同元素富集区起到了降低热导的作用。在785K时，Sn0.98Na0.016Ag0.004Se样品ZT值达到了1.24。.②针对高温热电材料选择范围窄的问题，研究了新型SmS热电材料的热电性能。结果表明，SmS具有高不对称能带特性，其电子电导率和空穴电导率差异可达数百倍，使得其高温热电性能不会受到双极化效应的影响。Se固溶的SmS热电优值在1123K时达到1.1，证明了窄带隙半导体中存在高温热电材料的可能性。.③针对室温热电材料，研究了Bi2Te3/Ti3C2Tx纳米复合材料热电性能研究，揭示了复合界面对与载流子及声子的散射机制。最后，以Bi2Te3热电材料为原料，开发出适用于3D打印、具有良好流动性能的球形Bi2Te3粉体气雾化制备方法，3D打印的Bi2Te3取向度和热导率降低，热电优值达0.3。