Redox-promoted tailoring of the high-temperature electrical performance in Ca3Co4O9 thermoelectric materials by metallic cobalt addition
Autor(a) principal: | |
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Data de Publicação: | 2020 |
Outros Autores: | , , , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10773/29057 |
Resumo: | This paper reports a novel composite-based processing route for improving the electrical performance of Ca3Co4O9 thermoelectric (TE) ceramics. The approach involves the addition of metallic Co, acting as a pore filler on oxidation, and considers two simple sintering schemes. The (1-x)Ca3Co4O9/xCo composites (x = 0%, 3%, 6% and 9% vol.) have been prepared through a modified Pechini method, followed by one- and two-stage sintering, to produce low-density (one-stage, 1ST) and high-density (two-stage, 2ST) ceramic samples. Their high-temperature TE properties, namely the electrical conductivity (σ), Seebeck coefficient (α) and power factor (PF), were investigated between 475 and 975 K, in air flow, and related to their respective phase composition, morphology and microstructure. For the 1ST case, the porous samples (56%-61% of ρth) reached maximum PF values of around 210 and 140 μWm-1·K-2 for the 3% and 6% vol. Co-added samples, respectively, being around two and 1.3 times higher than those of the pure Ca3Co4O9 matrix. Although 2ST sintering resulted in rather dense samples (80% of ρth), the efficiency of the proposed approach, in this case, was limited by the complex phase composition of the corresponding ceramics, impeding the electronic transport and resulting in an electrical performance below that measured for the Ca3Co4O9 matrix (224 μWm-1·K-2 at 975K). |
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Redox-promoted tailoring of the high-temperature electrical performance in Ca3Co4O9 thermoelectric materials by metallic cobalt additionCalcium cobaltiteTE performanceElectrical propertiesCompositeRedox tuningThis paper reports a novel composite-based processing route for improving the electrical performance of Ca3Co4O9 thermoelectric (TE) ceramics. The approach involves the addition of metallic Co, acting as a pore filler on oxidation, and considers two simple sintering schemes. The (1-x)Ca3Co4O9/xCo composites (x = 0%, 3%, 6% and 9% vol.) have been prepared through a modified Pechini method, followed by one- and two-stage sintering, to produce low-density (one-stage, 1ST) and high-density (two-stage, 2ST) ceramic samples. Their high-temperature TE properties, namely the electrical conductivity (σ), Seebeck coefficient (α) and power factor (PF), were investigated between 475 and 975 K, in air flow, and related to their respective phase composition, morphology and microstructure. For the 1ST case, the porous samples (56%-61% of ρth) reached maximum PF values of around 210 and 140 μWm-1·K-2 for the 3% and 6% vol. Co-added samples, respectively, being around two and 1.3 times higher than those of the pure Ca3Co4O9 matrix. Although 2ST sintering resulted in rather dense samples (80% of ρth), the efficiency of the proposed approach, in this case, was limited by the complex phase composition of the corresponding ceramics, impeding the electronic transport and resulting in an electrical performance below that measured for the Ca3Co4O9 matrix (224 μWm-1·K-2 at 975K).MDPI2020-08-13T16:25:39Z2020-03-01T00:00:00Z2020-03-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10773/29057eng1996-194410.3390/ma13051060Constantinescu, GabrielSarabando, Artur R.Rasekh, ShahedLopes, DiogoSergiienko, SergiiAmirkhizi, ParisaFrade, Jorge R.Kovalevsky, Andrei V.info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2024-02-22T11:56:11Zoai:ria.ua.pt:10773/29057Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T03:01:28.942632Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Redox-promoted tailoring of the high-temperature electrical performance in Ca3Co4O9 thermoelectric materials by metallic cobalt addition |
title |
Redox-promoted tailoring of the high-temperature electrical performance in Ca3Co4O9 thermoelectric materials by metallic cobalt addition |
spellingShingle |
Redox-promoted tailoring of the high-temperature electrical performance in Ca3Co4O9 thermoelectric materials by metallic cobalt addition Constantinescu, Gabriel Calcium cobaltite TE performance Electrical properties Composite Redox tuning |
title_short |
Redox-promoted tailoring of the high-temperature electrical performance in Ca3Co4O9 thermoelectric materials by metallic cobalt addition |
title_full |
Redox-promoted tailoring of the high-temperature electrical performance in Ca3Co4O9 thermoelectric materials by metallic cobalt addition |
title_fullStr |
Redox-promoted tailoring of the high-temperature electrical performance in Ca3Co4O9 thermoelectric materials by metallic cobalt addition |
title_full_unstemmed |
Redox-promoted tailoring of the high-temperature electrical performance in Ca3Co4O9 thermoelectric materials by metallic cobalt addition |
title_sort |
Redox-promoted tailoring of the high-temperature electrical performance in Ca3Co4O9 thermoelectric materials by metallic cobalt addition |
author |
Constantinescu, Gabriel |
author_facet |
Constantinescu, Gabriel Sarabando, Artur R. Rasekh, Shahed Lopes, Diogo Sergiienko, Sergii Amirkhizi, Parisa Frade, Jorge R. Kovalevsky, Andrei V. |
author_role |
author |
author2 |
Sarabando, Artur R. Rasekh, Shahed Lopes, Diogo Sergiienko, Sergii Amirkhizi, Parisa Frade, Jorge R. Kovalevsky, Andrei V. |
author2_role |
author author author author author author author |
dc.contributor.author.fl_str_mv |
Constantinescu, Gabriel Sarabando, Artur R. Rasekh, Shahed Lopes, Diogo Sergiienko, Sergii Amirkhizi, Parisa Frade, Jorge R. Kovalevsky, Andrei V. |
dc.subject.por.fl_str_mv |
Calcium cobaltite TE performance Electrical properties Composite Redox tuning |
topic |
Calcium cobaltite TE performance Electrical properties Composite Redox tuning |
description |
This paper reports a novel composite-based processing route for improving the electrical performance of Ca3Co4O9 thermoelectric (TE) ceramics. The approach involves the addition of metallic Co, acting as a pore filler on oxidation, and considers two simple sintering schemes. The (1-x)Ca3Co4O9/xCo composites (x = 0%, 3%, 6% and 9% vol.) have been prepared through a modified Pechini method, followed by one- and two-stage sintering, to produce low-density (one-stage, 1ST) and high-density (two-stage, 2ST) ceramic samples. Their high-temperature TE properties, namely the electrical conductivity (σ), Seebeck coefficient (α) and power factor (PF), were investigated between 475 and 975 K, in air flow, and related to their respective phase composition, morphology and microstructure. For the 1ST case, the porous samples (56%-61% of ρth) reached maximum PF values of around 210 and 140 μWm-1·K-2 for the 3% and 6% vol. Co-added samples, respectively, being around two and 1.3 times higher than those of the pure Ca3Co4O9 matrix. Although 2ST sintering resulted in rather dense samples (80% of ρth), the efficiency of the proposed approach, in this case, was limited by the complex phase composition of the corresponding ceramics, impeding the electronic transport and resulting in an electrical performance below that measured for the Ca3Co4O9 matrix (224 μWm-1·K-2 at 975K). |
publishDate |
2020 |
dc.date.none.fl_str_mv |
2020-08-13T16:25:39Z 2020-03-01T00:00:00Z 2020-03-01 |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10773/29057 |
url |
http://hdl.handle.net/10773/29057 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
1996-1944 10.3390/ma13051060 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
MDPI |
publisher.none.fl_str_mv |
MDPI |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
instname_str |
Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
repository.mail.fl_str_mv |
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1799137670256918528 |