Half-Heusler热电材料的研究进展

Recent Progress in Half-Heusler Thermoelectric Materials

Half-Heuslers热电材料由于热稳定性好、机械强度高,已成为中高温废热回收领域具有潜力的候选材料。在该材料体系中,p型和n型half-Heuslers的ZT值在最近几年得到逐步改善,其最高值已超过1.0。本文综述half-Heuslers体系的最新研究进展,包括纳米复合技术的应用、利用原子质量和尺寸差异增强合金散射、三元合金和新half-Heusler材料等,指出尽管half-Heusler的ZT值已经超过了1.0,但其成本仍然较高,如何降低half-Heusler材料的生产成本及优化新型half-Heusler材料将是未来的研究重点。目前,half-Heuslers的ZT值的提高仍具有较大的空间,如热压后样品的平均晶粒尺寸超过了100 nm,进一步降低晶粒尺寸可提高ZT值,开展势垒过滤效应在half-Heuslers中的应用也有望提高其热电性能。

Half - Heuslers thermoelectric materials are potential candidates for medium - to - high temperature waste heat recover- y, owing to their good thermal stability and mechanical strength. In this particular material system, the ZTs of both p - type and n - type half - Heuslers have improved gradually in recent years and its peaks have exceeded 1. O. This review serves as a guide to learn the recent progress in half - Heuslers system ： including the application of nanocomposite approach, enhanced alloy scattering by larger atomic and size differences and the exploration of ternary systems as well as new classes of materials. Though the ZTs of half - Heuslers have surpassed 1.0 , the cost is still high. Therefore, reducing the cost and optimizing the performance of the new half - Heuslers ma- terials will be the major study in the future. At present, enhancing the ZTs also has much potential. The average gain size of samples after hot pressing is more than 100 nm. So the further improvement of ZT will be realized by reducing the larger gain size. Meanwhile, the usage of energy filtering effect in half - Heuslers is expected to boost its thermoelectric properties.