Abstract
Thermoelectric materials offer the possibility of enhanced energy efficiency due to waste heat scavenging. Based on their high-temperature stability and ease of synthesis, efficient oxide-based thermoelectrics remain a tantalizing research goal; however, their current performance is significantly lower than the industry standards such as Bi2Te3 and PbTe. Among the oxide thermoelectrics studied thus far, the development of n-type thermoelectric oxides has fallen behind that of p-type oxides, primarily due to limitations on the overall dimensionless figure of merit, or ZT, by large lattice thermal conductivities. In this article, we propose a simple strategy based on chemical intuition to discover enhanced n-type oxide thermoelectrics. Using state-of-the-art calculations, we demonstrate that the PbSb2O6-structured BaBi2O6 represents a novel structural motif for thermoelectric materials, with a predicted ZT of 0.17–0.19. We then suggest two methods to enhance the ZT up to 0.22, on par with the current best earth-abundant n-type thermoelectric at around 600 K, SrTiO3, which has been much more heavily researched. Our analysis of the factors that govern the electronic and phononic scattering in this system provides a blueprint for optimizing ZT beyond the perfect crystal approximation.
Original language | English |
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Pages (from-to) | 7441-7456 |
Number of pages | 16 |
Journal | Chemistry of Materials |
Volume | 33 |
Issue number | 18 |
Early online date | 7 Sept 2021 |
DOIs | |
Publication status | Published - 28 Sept 2021 |
Bibliographical note
Acknowledgments:Via our membership of the United Kingdom’s HEC Materials Chemistry Consortium, which is funded by EPSRC (EP/L000202, EP/R029431, EP/T022213), this work used the ARCHER U.K. National Supercomputing Service (http://www.archer.ac.uk) and the U.K. Materials and Molecular Modelling Hub for computational resources, MMM Hub, which is also partially funded by EPSRC (EP/P020194 and EP/T022213). This work used the ARCHER2 U.K. National Supercomputing Service (https://www.archer2.ac.uk). The authors acknowledge the use of the UCL Legion, Myriad, Grace, and Kathleen High Throughput Computing Facilities (Legion@UCL, Myriad@UCL, Grace@UCL, and Kathleen@UCL) and associated support services in the completion of this work. D.O.S. acknowledges support from the EPSRC (EP/N01572X/1). D.O.S. acknowledges membership of the Materials Design Network. A.M.G. acknowledges Diamond Light Source for the cosponsorship of a studentship on the EPSRC Centre for Doctoral Training in Molecular Modelling and Materials Science (EP/L015862/1).