Publication: Enhanced thermoelectric performance in Mg3+xSb1.5Bi0.49Te0.01 via engineering microstructure through melt-centrifugation
Program
KU Authors
Co-Authors
Candolfi, Christophe
Veremchuk, Igor
Kaiser, Felix
Burkhardt, Ulrich
Snyder, G. Jeffrey
Grin, Yuri
Publication Date
Language
Type
Embargo Status
Journal Title
Journal ISSN
Volume Title
Alternative Title
Abstract
N-type Zintl phases with earth-abundant and non-toxic constituent elements have attracted intense research interest thanks to their high thermoelectric efficiencies in the mid-temperature range, exemplified by the recently discovered Mg3Sb2 material. In this study, the liquid phase is expelled from the microstructure of the optimized n-type phase Mg3+xSb1.5Bi0.49Te0.01 by applying a meltcentrifugation technique leading to the formation of lattice dislocations, grain boundary dislocations and increasing porosity. Additional phonon scattering mechanisms were introduced in the microstructure through this manufacturing method, resulting in a significant 50% reduction in the total thermal conductivity from similar to 1 W m(-1) K-1 to similar to 0.5 W m(-1) K-1 at 723 K. Combined with high power factors, this reduced heat transport leads to a dimensionless thermoelectric figure of merit, zT, value of similar to 1.64 at 723 K, 43% higher than the value obtained in untreated Mg3+xSb1.5Bi0.49Te0.01 (zT similar to 1.14 at 723 K). This peak zT value yields a predicted device ZT of 0.95, and a promising theoretical thermoelectric efficiency of about 12%. These results further underline the great potential of the lightweight Mg3Sb2 material for midtemperature energy harvesting via thermoelectric effects.
Source
Publisher
Royal Society of Chemistry (RSC)
Subject
Chemistry, Physical chemistry, Energy, Fuels, Materials Science
Citation
Has Part
Source
Journal of Materials Chemistry A
Book Series Title
Edition
DOI
10.1039/d0ta09993g