Mechanically robust BiSbTe alloys with superior thermoelectric performance: A case study of stable hierarchical nanostructured thermoelectric materials

Yun Zheng, Qiang Zhang, Xianli Su*, Hongyao Xie, Shengcheng Shu, Tianle Chen, Gangjian Tan, Yonggao Yan, Xinfeng Tang, Ctirad Uher, G. Jeffrey Snyder

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

206 Scopus citations

Abstract

Bismuth telluride based thermoelectric materials have been commercialized for a wide range of applications in power generation and refrigeration. However, the poor machinability and susceptibility to brittle fracturing of commercial ingots often impose significant limitations on the manufacturing process and durability of thermoelectric devices. In this study, melt spinning combined with a plasma-activated sintering (MS-PAS) method is employed for commercial p-type zone-melted (ZM) ingots of Bi0.5Sb1.5Te3. This fast synthesis approach achieves hierarchical structures and in-situ nanoscale precipitates, resulting in the simultaneous improvement of the thermoelectric performance and the mechanical properties. Benefitting from a strong suppression of the lattice thermal conductivity, a peak ZT of 1.22 is achieved at 340 K in MS-PAS synthesized structures, representing about a 40% enhancement over that of ZM ingots. Moreover, MS-PAS specimens with hierarchical structures exhibit superior machinability and mechanical properties with an almost 30% enhancement in their fracture toughness, combined with an eightfold and a factor of six increase in the compressive and flexural strength, respectively. Accompanied by an excellent thermal stability up to 200 °C for the MS-PAS synthesized samples, the MS-PAS technique demonstrates great potential for mass production and large-scale applications of Bi2Te3 related thermoelectrics. Melt-spinning combined with plasma activated sintering is adopted to design hierarchical nanostructured BiSbTe alloys. Because of the hierarchical configuration and nanodispersion, the lattice thermal conductivity is reduced significantly, leading to superior thermoelectric performance and robust mechanical properties. Accompanied by an excellent thermal stability, the melt-spinning-based synthesis approach offers great potential for commercial applications.

Original languageEnglish (US)
Article number1401391
JournalAdvanced Energy Materials
Volume5
Issue number5
DOIs
StatePublished - Mar 1 2015

Keywords

  • alloys
  • hierarchical structures
  • nanostructures
  • thermoelectric materials

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Materials Science(all)

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