Journal Home > Volume 10 , issue 2

Oxide-based ceramics could be promising thermoelectric materials because of their thermal and chemical stability at high temperature. However, their mediocre electrical conductivity or high thermal conductivity is still a challenge for the use in commercial devices. Here, we report significantly suppressed thermal conductivity in SrTiO3-based thermoelectric ceramics via high-entropy strategy for the first time, and optimized electrical conductivity by defect engineering. In high-entropy (Ca0.2Sr0.2Ba0.2Pb0.2La0.2)TiO3 bulks, the minimum thermal conductivity can be 1.17 W/(m·K) at 923 K, which should be ascribed to the large lattice distortion and the huge mass fluctuation effect. The power factor can reach about 295 μW/(m·K2) by inducing oxygen vacancies. Finally, the ZT value of 0.2 can be realized at 873 K in this bulk sample. This approach proposed a new concept of high entropy into thermoelectric oxides, which could be generalized for designing high-performance thermoelectric oxides with low thermal conductivity.


menu
Abstract
Full text
Outline
About this article

Electrical and thermal transport behaviours of high-entropy perovskite thermoelectric oxides

Show Author's information Yunpeng ZHENGaMingchu ZOUaWenyu ZHANGaDi YIaJinle LANbCe-Wen NANaYuan-Hua LINa( )
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China

Abstract

Oxide-based ceramics could be promising thermoelectric materials because of their thermal and chemical stability at high temperature. However, their mediocre electrical conductivity or high thermal conductivity is still a challenge for the use in commercial devices. Here, we report significantly suppressed thermal conductivity in SrTiO3-based thermoelectric ceramics via high-entropy strategy for the first time, and optimized electrical conductivity by defect engineering. In high-entropy (Ca0.2Sr0.2Ba0.2Pb0.2La0.2)TiO3 bulks, the minimum thermal conductivity can be 1.17 W/(m·K) at 923 K, which should be ascribed to the large lattice distortion and the huge mass fluctuation effect. The power factor can reach about 295 μW/(m·K2) by inducing oxygen vacancies. Finally, the ZT value of 0.2 can be realized at 873 K in this bulk sample. This approach proposed a new concept of high entropy into thermoelectric oxides, which could be generalized for designing high-performance thermoelectric oxides with low thermal conductivity.

Keywords:

high entropy, thermoelectric oxides, thermal conductivity, electrical conductivity, oxygen vacancy
Received: 15 January 2021 Accepted: 21 January 2021 Published: 29 January 2021 Issue date: April 2021
References(33)
[1]
K Nielsch, J Bachmann, J Kimling, et al. Thermoelectric nanostructures: From physical model systems towards nanograined composites. Adv Energy Mater 2011, 1: 713-731.
[2]
YZ Pei, XY Zhou, TJ Zhu. Editorial for rare metals, special issue on advanced thermoelectric materials. Rare Met 2018, 37: 257-258.
[3]
ZF Zhou, GK Ren, X Tan, et al. Enhancing the thermoelectric performance of ZnO epitaxial films by Ga doping and thermal tuning. J Mater Chem A 2018, 6: 24128-24135.
[4]
KF Cai, E Müller, C Drašar, et al. Preparation and thermoelectric properties of Al-doped ZnO ceramics. Mat Sci Eng B 2003, 104: 45-48.
[5]
JF Baumard, E Tani. Thermoelectric power in reduced pure and Nb-doped TiO2 rutile at high temperature. Phys Status Solidi a 1977, 39: 373-382.
[6]
M Ohtaki, D Ogura, K Eguchi, et al. High-temperature thermoelectric properties of In2O3-based mixed oxides and their applicability to thermoelectric power generation. J Mater Chem 1994, 4: 653.
[7]
LD Zhao, D Berardan, YL Pei, et al. Bi1-xSrxCuSeO oxyselenides as promising thermoelectric materials. Appl Phys Lett 2010, 97: 092118.
[8]
R Liu, X Tan, YC Liu, et al. BiCuSeO as state-of-the-art thermoelectric materials for energy conversion: From thin films to bulks. Rare Metal 2018, 37: 259-273.
[9]
R Liu, JL Lan, X Tan, et al. Carrier concentration optimization for thermoelectric performance enhancement in n-type Bi2O2Se. J Eur Ceram Soc 2018, 38: 2742-2746.
[10]
M Ito, D Furumoto. Effects of noble metal addition on microstructure and thermoelectric properties of NaxCo2O4. J Alloys Compd 2008, 450: 494-498.
[11]
Y Wang, Y Sui, JG Cheng, et al. High temperature transport and thermoelectric properties of Ag-substituted Ca3Co4O9+δ system. J Alloys Compd 2008, 448: 1-5.
[12]
JQ Ye, HD Li, QL He. Thermoelectric properties of Bi1.5Pb0.5Sr2-xLaxCo2Oy polycrystalline materials. Rare Met 2011, 30: 501-504.
[13]
HC Wang, CL Wang, WB Su, et al. Doping effect of La and Dy on the thermoelectric properties of SrTiO3. J Am Ceram Soc 2011, 94: 838-842.
[14]
G Xu. High-temperature transport properties of Nb and Ta substituted CaMnO3 system. Solid State Ionics 2004, 171: 147-151.
[15]
GJ Snyder, ES Toberer. Complex thermoelectric materials. Nat Mater 2008, 7: 105-114.
[16]
SR Popuri, R Decourt, JA McNulty, et al. Phonon-glass and heterogeneous electrical transport in A-site-deficient SrTiO3. J Phys Chem C 2019, 123: 5198-5208.
[17]
J Wang, BY Zhang, HJ Kang, et al. Record high thermoelectric performance in bulk SrTiO3 via nano-scale modulation doping. Nano Energy 2017, 35: 387-395.
[18]
MT Dylla, JJ Kuo, I Witting, et al. Grain boundary engineering nanostructured SrTiO3 for thermoelectric applications. Adv Mater Interfaces 2019, 6: 1900222.
[19]
C Wu, J Li, YC Fan, et al. The effect of reduced graphene oxide on microstructure and thermoelectric properties of Nb-doped A-site-deficient SrTiO3 ceramics. J Alloys Compd 2019, 786: 884-893.
[20]
O Okhay, S Zlotnik, WJ Xie, et al. Thermoelectric performance of Nb-doped SrTiO3 enhanced by reduced graphene oxide and Sr deficiency cooperation. Carbon 2019, 143: 215-222.
[21]
CM Rost, E Sachet, T Borman, et al. Entropy-stabilized oxides. Nat Commun 2015, 6: 8485.
[22]
J Liu, G Shao, D Liu, et al. Design and synthesis of chemically complex ceramics from the perspective of entropy. Mater Today Adv 2020, 8: 100114.
[23]
C Oses, C Toher, S Curtarolo. High-entropy ceramics. Nat Rev Mater 2020, 5: 295-309.
[24]
J Gild, M Samiee, JL Braun, et al. High-entropy fluorite oxides. J Eur Ceram Soc 2018, 38: 3578-3584.
[25]
ZF Zhao, HM Xiang, H Chen, et al. High-entropy (Nd0.2Sm0.2Eu0.2Y0.2Yb0.2)4Al2O9 with good high temperature stability, low thermal conductivity, and anisotropic thermal expansivity. J Adv Ceram 2020, 9: 595-605.
[26]
K-Y Tsai, M-H Tsai, J-W Yeh. Sluggish diffusion in Co-Cr-Fe-Mn-Ni high-entropy alloys. Acta Mater 2013, 61: 4887-4897.
[27]
YF Ye, Q Wang, J Lu, et al. High-entropy alloy: Challenges and prospects. Mater Today 2016, 19: 349-362.
[28]
C Lee, G Song, MC Gao, et al. Lattice distortion in a strong and ductile refractory high-entropy alloy. Acta Mater 2018, 160: 158-172.
[29]
S Shibagaki, K Fukushima. XPS analysis on Nb-SrTiO3 thin films deposited with pulsed laser ablation technique. J Eur Ceram Soc 1999, 19: 1423-1426.
[30]
SR Popuri, AJM Scott, RA Downie, et al. Glass-like thermal conductivity in SrTiO3 thermoelectrics induced by A-site vacancies. RSC Adv 2014, 4: 33720-33723.
[31]
GK Ren, JL Lan, KJ Ventura, et al. Contribution of point defects and nano-grains to thermal transport behaviours of oxide-based thermoelectrics. npj Comput Mater 2016, 2: 16023.
[32]
GJ Snyder, AH Snyder, M Wood, et al. Weighted mobility. Adv Mater 2020, 32: 2001537.
[33]
M Cutler, JF Leavy, RL Fitzpatrick. Electronic transport in semimetallic cerium sulfide. Phys Rev 1964, 133: a1143.
Publication history
Copyright
Acknowledgements
Rights and permissions

Publication history

Received: 15 January 2021
Accepted: 21 January 2021
Published: 29 January 2021
Issue date: April 2021

Copyright

© The Author(s) 2021

Acknowledgements

We thank Yu Xiao from Beihang University for samples’ thermal conductivity measurements. This work was financially supported by Basic Science Center Project of the National Natural Science Foundation of China under Grant No. 51788104, National Key Research Program of China under Grant No. 2016YFA0201003, and the National Natural Science Foundation of China under Grant No. 51729201.

Rights and permissions

This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made.

The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.

Reprints and Permission requests may be sought directly from editorial office.

Return