Issue 10, 2019

3D Printing of highly textured bulk thermoelectric materials: mechanically robust BiSbTe alloys with superior performance

Abstract

While zone-melted (ZM) Bi2Te3 is a standard commercially available thermoelectric (TE) material, it suffers from not being sufficiently mechanically robust due to the presence of the van der Waals bonded Te–Te layers that reduce the product yield and compromise operational reliability. Polycrystalline materials prepared by powder metallurgy techniques exhibit improved mechanical properties but usually lose the desired texture exhibited by ZM ingots, and this affects their TE performance. It is highly desirable to be able to fabricate Bi2Te3-based bulk materials with anisotropies similar to a single crystal, yet being mechanically strong as the polycrystalline specimens. Herein, we combine for the first time the thermal explosion technique with selective laser melting (SLM) to synthesize the highly textured p-type Bi0.4Sb1.6Te3 bulk material. Structural analysis (FESEM and XRD) indicates that the slender columnar grains grew along the building direction (BD) of the structure and the orientation factor reached up to 0.9, close to that representing a single crystal. TEM images revealed a high density of dislocations inside the grains. Since the printed compound has a high degree of texture, the TE and mechanical properties exhibit a highly anisotropic behavior. The maximum ZT of annealed samples parallel to the BD was 1.1, similar to that of the single crystal. However, the compressive strength of the structure reached up to 91 MPa, some 2.5 times the strength of a typical single crystal (37 MPa), and even higher than that of Spark Plasma Sintered (SPS) polycrystalline samples (80 MPa). Meanwhile, the mechanical cutting performance was much superior compared to that of the ZM ingot, and TE legs could be cut to sizes as small as 0.2 mm. A micro-TE module assembled using SLM-printed high performance p-type BiSbTe and SPS-compacted n-type BiTeSe materials showed the maximum cooling temperature difference of 62 °C. The work provides a facile and effective solution for preparation of Bi2Te3-based materials with high texture, robust mechanical properties, and excellent TE performance. As such, it lays a solid foundation for rapid in situ 3D printing of Bi2Te3-based micro-TE devices.

Graphical abstract: 3D Printing of highly textured bulk thermoelectric materials: mechanically robust BiSbTe alloys with superior performance

Supplementary files

Article information

Article type
Paper
Submitted
28 Jun 2019
Accepted
22 Ago 2019
First published
23 Ago 2019

Energy Environ. Sci., 2019,12, 3106-3117

3D Printing of highly textured bulk thermoelectric materials: mechanically robust BiSbTe alloys with superior performance

J. Qiu, Y. Yan, T. Luo, K. Tang, L. Yao, J. Zhang, M. Zhang, X. Su, G. Tan, H. Xie, M. G. Kanatzidis, C. Uher and X. Tang, Energy Environ. Sci., 2019, 12, 3106 DOI: 10.1039/C9EE02044F

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements