Assessing cell polarity reversal degradation phenomena in PEM fuel cells by electrochemical impedance sectroscopy
Autor(a) principal: | |
---|---|
Data de Publicação: | 2013 |
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/10400.9/1983 |
Resumo: | Electrochemical impedance spectroscopy (EIS) is identified as one of the most promising in-situ diagnostics tools available for assessing fuel cell ageing and degradation. In this work, the degradation phenomena caused by cell polarity reversal due to fuel starvation of an open cathode 16 membrane electrode assembly (MEA) – low power (PEM) fuel cell (15 W nominal power) – is reported using EIS as a base technique. Measuring the potential of individual cells, while the fuel cell is on load, was found instrumental in assessing the “state of health” of cells at fixed current. Location of affected cells, those farthest away from hydrogen entry in the stack, was revealed by very low or even negative potential values. EIS spectra were taken at selected break-in periods during fuel cell functioning. The analysis of impedance data was made using an a priori equivalent circuit describing the transfer function of the system in question –equivalent circuit elements were evaluated by a complex non-linear least square (CNLS) fitting algorithm, and by calculating and analyzing the corresponding distribution of relaxation times (DRT). Results and interpretation of cell polarity reversal due to hydrogen starvation were complemented with ex-situ MEA cross section analysis, using scanning electron microscopy. Electrode thickness reduction and delamination of catalyst layers were observed as a result of reactions taking place during hydrogen starvation. Carbon corrosion and membrane degradation by fluoride depletion are discussed. |
id |
RCAP_ccb34bfb5eedc552168909b27fcad4e1 |
---|---|
oai_identifier_str |
oai:repositorio.lneg.pt:10400.9/1983 |
network_acronym_str |
RCAP |
network_name_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository_id_str |
7160 |
spelling |
Assessing cell polarity reversal degradation phenomena in PEM fuel cells by electrochemical impedance sectroscopyPEMDegradation mechanismsFuel starvationCatalyst lossElectrochemicalSpectroscopyDistribution relaxation timesFuel cellsElectrochemical impedance spectroscopy (EIS) is identified as one of the most promising in-situ diagnostics tools available for assessing fuel cell ageing and degradation. In this work, the degradation phenomena caused by cell polarity reversal due to fuel starvation of an open cathode 16 membrane electrode assembly (MEA) – low power (PEM) fuel cell (15 W nominal power) – is reported using EIS as a base technique. Measuring the potential of individual cells, while the fuel cell is on load, was found instrumental in assessing the “state of health” of cells at fixed current. Location of affected cells, those farthest away from hydrogen entry in the stack, was revealed by very low or even negative potential values. EIS spectra were taken at selected break-in periods during fuel cell functioning. The analysis of impedance data was made using an a priori equivalent circuit describing the transfer function of the system in question –equivalent circuit elements were evaluated by a complex non-linear least square (CNLS) fitting algorithm, and by calculating and analyzing the corresponding distribution of relaxation times (DRT). Results and interpretation of cell polarity reversal due to hydrogen starvation were complemented with ex-situ MEA cross section analysis, using scanning electron microscopy. Electrode thickness reduction and delamination of catalyst layers were observed as a result of reactions taking place during hydrogen starvation. Carbon corrosion and membrane degradation by fluoride depletion are discussed.ElsevierRepositório do LNEGTravassos, Maria AntóniaLopes, Vitor V.Silva, R. A.Novais, Augusto Q.Rangel, C. M.2013-09-17T09:02:08Z20132013-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10400.9/1983engTravassos, M.A.; Lopes, Vitor V.; Silva, R.A.; Novais, A.Q.; Rangel, C.M. Assessing cell polarity reversal degradation phenomena in PEM fuel cells by electrochemical impedance sectroscopy. In: International Journal of Hydrogen Energy, 2013, vol. 38, nº 18, p. 7684-76960360-3199info: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:RCAAP2024-02-18T07:43:00Zoai:repositorio.lneg.pt:10400.9/1983Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T15:34:50.376949Repositório 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 |
Assessing cell polarity reversal degradation phenomena in PEM fuel cells by electrochemical impedance sectroscopy |
title |
Assessing cell polarity reversal degradation phenomena in PEM fuel cells by electrochemical impedance sectroscopy |
spellingShingle |
Assessing cell polarity reversal degradation phenomena in PEM fuel cells by electrochemical impedance sectroscopy Travassos, Maria Antónia PEM Degradation mechanisms Fuel starvation Catalyst loss Electrochemical Spectroscopy Distribution relaxation times Fuel cells |
title_short |
Assessing cell polarity reversal degradation phenomena in PEM fuel cells by electrochemical impedance sectroscopy |
title_full |
Assessing cell polarity reversal degradation phenomena in PEM fuel cells by electrochemical impedance sectroscopy |
title_fullStr |
Assessing cell polarity reversal degradation phenomena in PEM fuel cells by electrochemical impedance sectroscopy |
title_full_unstemmed |
Assessing cell polarity reversal degradation phenomena in PEM fuel cells by electrochemical impedance sectroscopy |
title_sort |
Assessing cell polarity reversal degradation phenomena in PEM fuel cells by electrochemical impedance sectroscopy |
author |
Travassos, Maria Antónia |
author_facet |
Travassos, Maria Antónia Lopes, Vitor V. Silva, R. A. Novais, Augusto Q. Rangel, C. M. |
author_role |
author |
author2 |
Lopes, Vitor V. Silva, R. A. Novais, Augusto Q. Rangel, C. M. |
author2_role |
author author author author |
dc.contributor.none.fl_str_mv |
Repositório do LNEG |
dc.contributor.author.fl_str_mv |
Travassos, Maria Antónia Lopes, Vitor V. Silva, R. A. Novais, Augusto Q. Rangel, C. M. |
dc.subject.por.fl_str_mv |
PEM Degradation mechanisms Fuel starvation Catalyst loss Electrochemical Spectroscopy Distribution relaxation times Fuel cells |
topic |
PEM Degradation mechanisms Fuel starvation Catalyst loss Electrochemical Spectroscopy Distribution relaxation times Fuel cells |
description |
Electrochemical impedance spectroscopy (EIS) is identified as one of the most promising in-situ diagnostics tools available for assessing fuel cell ageing and degradation. In this work, the degradation phenomena caused by cell polarity reversal due to fuel starvation of an open cathode 16 membrane electrode assembly (MEA) – low power (PEM) fuel cell (15 W nominal power) – is reported using EIS as a base technique. Measuring the potential of individual cells, while the fuel cell is on load, was found instrumental in assessing the “state of health” of cells at fixed current. Location of affected cells, those farthest away from hydrogen entry in the stack, was revealed by very low or even negative potential values. EIS spectra were taken at selected break-in periods during fuel cell functioning. The analysis of impedance data was made using an a priori equivalent circuit describing the transfer function of the system in question –equivalent circuit elements were evaluated by a complex non-linear least square (CNLS) fitting algorithm, and by calculating and analyzing the corresponding distribution of relaxation times (DRT). Results and interpretation of cell polarity reversal due to hydrogen starvation were complemented with ex-situ MEA cross section analysis, using scanning electron microscopy. Electrode thickness reduction and delamination of catalyst layers were observed as a result of reactions taking place during hydrogen starvation. Carbon corrosion and membrane degradation by fluoride depletion are discussed. |
publishDate |
2013 |
dc.date.none.fl_str_mv |
2013-09-17T09:02:08Z 2013 2013-01-01T00:00:00Z |
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/10400.9/1983 |
url |
http://hdl.handle.net/10400.9/1983 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Travassos, M.A.; Lopes, Vitor V.; Silva, R.A.; Novais, A.Q.; Rangel, C.M. Assessing cell polarity reversal degradation phenomena in PEM fuel cells by electrochemical impedance sectroscopy. In: International Journal of Hydrogen Energy, 2013, vol. 38, nº 18, p. 7684-7696 0360-3199 |
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 |
Elsevier |
publisher.none.fl_str_mv |
Elsevier |
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 |
|
_version_ |
1799130212945887232 |