Improved High Temperature Thermoelectric Properties in Misfit Ca3Co4O9 by Thermal Annealing
Chatterjee, Arindom (Institut Català de Nanociència i Nanotecnologia)
Sachat, Alexandros el (National Center for Scientific Research "Demokritos")
Banik, Ananya (Jawaharlal Nehru Centre for Advanced Scientific Research)
Biswas, Kanishka (Jawaharlal Nehru Centre for Advanced Scientific Research)
Castro-Alvarez, Alejandro (Universidad de La Frontera. Centro de Excelencia en Medicina Traslacional (Chile))
Sotomayor Torres, Clivia M. (Institut Català de Nanociència i Nanotecnologia)
Santiso, José (Institut Català de Nanociència i Nanotecnologia)
Chávez Ángel, Emigdio (Institut Català de Nanociència i Nanotecnologia)

Date:	2023
Abstract:	CaCoO, a p-type thermoelectric material based on transition-metal oxides, has garnered significant interest due to its potential in thermoelectric applications. Its unique misfit-layered crystal structure contributes to low thermal conductivity and a high Seebeck coefficient, leading to a thermoelectric figure of merit (zT) of ≥1 at 1000 K. Conventionally, it has been believed that thermopower reaches its upper limit above 200 K. However, our thermopower measurements on polycrystalline CaCoO samples have revealed an unexpected increase in thermopower above 380 K. In this study, we investigate the effects of high oxygen pressure annealing on CaCoO and provide an explanation based on the mixed oxide states of cobalt and carrier hopping. Our results demonstrate that annealing induces modifications in the defect chemistry of CaCoO, leading to a decrease in electron hopping probability and the emergence of a thermal activation-like behavior in thermopower. These findings carry significant implications for the design and optimization of thermoelectric materials based on misfit cobaltates, opening new avenues for enhanced thermoelectric performance.
Grants:	European Commission 645658 European Commission 101029727 Ministerio de Economía y Competitividad FIS2015-70862-P Ministerio de Economía y Competitividad MAT2016-77100-C2-1-P Ministerio de Economía y Competitividad SEV-2017-0706
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Published in:	Energies, Vol. 16, Issue 13 (July 2023) , art. 5162, ISSN 1996-1073

DOI: 10.3390/en16135162

13 p, 3.8 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles