Mecanismos eletroquímicos nos processos de descarga do sistema PbO2/H2SO4
Autor(a) principal: | |
---|---|
Data de Publicação: | 2017 |
Tipo de documento: | Tese |
Idioma: | por |
Título da fonte: | Repositório Institucional da UFSCAR |
Texto Completo: | https://repositorio.ufscar.br/handle/ufscar/10011 |
Resumo: | The goal of this work was to seek a mechanistic and morphological understanding of the discharge process of lead-acid batteries’ positive plates, which exhibits a complex porous structure. Due to this fact, nonporous electrodes, ideally porous electrodes and positive plates were investigated. Studies on the discharge process of nonporous electrodes facilitated the reactional processes understanding from a mechanistic and morphological point of view. It was shown the existence of two steps during the discharge process. The first step is easily invertible and follows a solid state reaction mechanism, in which is possible to calculate the ionic resistivity evolution during the voltametric transient. The discharge product of the first step seems to be a PbOn1 electronic conductor (due to its stoichiometry) and, from the fact that it is a very thin film attached to the surface, this product was not observable by SEM measurements. On the other hand, the second step is not easily invertible and occurs at slower rates. During the second step, there is a stoichiometric change on the discharge product of the first step, giving rise to a PbOn2 (unstable and electronic insulator) that reacts with H2SO4 on the solution and forms lead basic sulfates. By the end of the second step, the discharge products give rise to structures observable by SEM measurements, which result from a dissolution/precipitation mechanism (that may occur due to longer processes times). The final stationary potential for discharge process of the PbO2/H2SO4 system was determined. Studies on ideally porous electrodes made it clear the existence of a zonal character of the discharge reactions. Studies on positive plates allowed the understanding of how complex the kinetic processes are on porous electrodes when compared to nonporous systems. Due to the structural complexity and the reactional zonal character, the transformations are much slower (time order of months). Besides that, the equilibrium O2/H2O must be taken into account to understand the results on positive plates, due to O2 bubbles trapped inside the pores during previous charge processes. These interpretations were made possible by Open Circuit Potential measurements assisted by concepts of Mixed Potential and Dynamical Systems Theories, specially the concept of attractor. This methodology allowed a new approach to electrochemical processes that implies multiple electrodes. |
id |
SCAR_ac1c23fd80634b42b28903a3b0e7b05a |
---|---|
oai_identifier_str |
oai:repositorio.ufscar.br:ufscar/10011 |
network_acronym_str |
SCAR |
network_name_str |
Repositório Institucional da UFSCAR |
repository_id_str |
4322 |
spelling |
Freitas, Heverson RenanD'Alkaine, Carlos Venturahttp://lattes.cnpq.br/8699821828310072http://lattes.cnpq.br/88298707666090441bc084c5-2db5-4b94-b79c-625c01d6c2ca2018-05-15T00:00:08Z2018-05-15T00:00:08Z2017-11-17FREITAS, Heverson Renan. Mecanismos eletroquímicos nos processos de descarga do sistema PbO2/H2SO4. 2017. Tese (Doutorado em Química) – Universidade Federal de São Carlos, São Carlos, 2017. Disponível em: https://repositorio.ufscar.br/handle/ufscar/10011.https://repositorio.ufscar.br/handle/ufscar/10011The goal of this work was to seek a mechanistic and morphological understanding of the discharge process of lead-acid batteries’ positive plates, which exhibits a complex porous structure. Due to this fact, nonporous electrodes, ideally porous electrodes and positive plates were investigated. Studies on the discharge process of nonporous electrodes facilitated the reactional processes understanding from a mechanistic and morphological point of view. It was shown the existence of two steps during the discharge process. The first step is easily invertible and follows a solid state reaction mechanism, in which is possible to calculate the ionic resistivity evolution during the voltametric transient. The discharge product of the first step seems to be a PbOn1 electronic conductor (due to its stoichiometry) and, from the fact that it is a very thin film attached to the surface, this product was not observable by SEM measurements. On the other hand, the second step is not easily invertible and occurs at slower rates. During the second step, there is a stoichiometric change on the discharge product of the first step, giving rise to a PbOn2 (unstable and electronic insulator) that reacts with H2SO4 on the solution and forms lead basic sulfates. By the end of the second step, the discharge products give rise to structures observable by SEM measurements, which result from a dissolution/precipitation mechanism (that may occur due to longer processes times). The final stationary potential for discharge process of the PbO2/H2SO4 system was determined. Studies on ideally porous electrodes made it clear the existence of a zonal character of the discharge reactions. Studies on positive plates allowed the understanding of how complex the kinetic processes are on porous electrodes when compared to nonporous systems. Due to the structural complexity and the reactional zonal character, the transformations are much slower (time order of months). Besides that, the equilibrium O2/H2O must be taken into account to understand the results on positive plates, due to O2 bubbles trapped inside the pores during previous charge processes. These interpretations were made possible by Open Circuit Potential measurements assisted by concepts of Mixed Potential and Dynamical Systems Theories, specially the concept of attractor. This methodology allowed a new approach to electrochemical processes that implies multiple electrodes.O objetivo desse trabalho foi buscar a compreensão mecanística e morfológica da descarga das placas positivas das baterias de chumbo ácido, as quais possuem uma complexa estrutura porosa. Devido a isso, eletrodos de PbO2 não porosos, porosos ideais e placas positivas foram investigadas. Estudos dos processos de descarga em eletrodos não porosos facilitaram a compreensão dos processos reacionais de um ponto de vista mecanístico e morfológico. Mostrou-se a existência de duas etapas durante a descarga. A 1ª etapa é facilmente invertível e segue um mecanismo de reação de estado sólido, sendo possível o cálculo da resistividade iônica durante o transiente voltamétrico. O produto da 1ª etapa parece ser um PbOn1 condutor eletrônico (devido à sua estequiometria) e, dada sua espessura e o fato de estar colado sobre a superfície, tal produto não pôde ser observado via MEV. Por outro lado, a 2ª etapa não é facilmente invertível e ocorre a taxas mais lentas. Durante a 2ª etapa há a mudança estequiométrica dos produtos da 1ª etapa, formando um PbOn2 (instável e isolante eletrônico) que reage com o H2SO4 ¬em solução para formar sulfatos básicos de chumbo. Ao final da 2ª etapa, os produtos formam estruturas visíveis em MEV e são resultado de um mecanismo de dissolução/precipitação (que pode ocorrer devido aos maiores tempos decorridos). O potencial estacionário final de descarga para o sistema PbO2/H2SO4 foi determinado. Os estudos em eletrodos porosos ideais deixaram clara a existência do caráter zonal da descarga. Os estudos em placas permitiram compreender como a cinética estabelecida para eletrodos não porosos se complica ao passar aos eletrodos porosos. Dada a complexidade da estrutura e a zonalidade da reação, as transformações ocorrem muito mais lentamente (da ordem de meses). Além disso, o equilíbrio O2/H2O deve ser considerado para interpretação dos resultados em placas, devido às bolhas de O2 retidas no interior dos poros durante cargas prévias. Todas essas interpretações só foram possíveis graças à medidas de potencial de circuito aberto assistidas pelas Teorias dos Potenciais Mistos e dos Sistemas Dinâmicos, em especial o conceito de atratores. Esta metodologia permitiu uma nova aproximação aos processos eletroquímicos que implicam eletrodos múltiplos.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPq: 163370/2012-5porUniversidade Federal de São CarlosCâmpus São CarlosPrograma de Pós-Graduação em Química - PPGQUFSCarBaterias de chumbo-ácidoDióxido de chumboFilmes de passivaçãoReação de estado sólidoPlaca positivaLead-acid batteryLead dioxidePassivation filmsSolid state reactionsPositive plateCIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICA::CINETICA QUIMICA E CATALISECIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICA::ELETROQUIMICACIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICAMecanismos eletroquímicos nos processos de descarga do sistema PbO2/H2SO4Electrochemichal mechanisms in the discharge processes of PbO2/H2SO4 systeminfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/doctoralThesisOnline600600143b0d3a-e240-4428-9335-3a5c32e5bfebinfo:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFSCARinstname:Universidade Federal de São Carlos (UFSCAR)instacron:UFSCARLICENSElicense.txtlicense.txttext/plain; charset=utf-81957https://repositorio.ufscar.br/bitstream/ufscar/10011/4/license.txtae0398b6f8b235e40ad82cba6c50031dMD54ORIGINALFREITAS_Heverson_2018.pdfFREITAS_Heverson_2018.pdfapplication/pdf20661878https://repositorio.ufscar.br/bitstream/ufscar/10011/5/FREITAS_Heverson_2018.pdfe4f084c40f6857f77515e94fc1ed7053MD55TEXTFREITAS_Heverson_2018.pdf.txtFREITAS_Heverson_2018.pdf.txtExtracted texttext/plain358887https://repositorio.ufscar.br/bitstream/ufscar/10011/6/FREITAS_Heverson_2018.pdf.txt32608b62187347a37c023120e26f4d00MD56THUMBNAILFREITAS_Heverson_2018.pdf.jpgFREITAS_Heverson_2018.pdf.jpgIM Thumbnailimage/jpeg9628https://repositorio.ufscar.br/bitstream/ufscar/10011/7/FREITAS_Heverson_2018.pdf.jpga0fd8d31a348b6074a6e8037ff7addb5MD57ufscar/100112023-09-18 18:31:14.879oai:repositorio.ufscar.br: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Repositório InstitucionalPUBhttps://repositorio.ufscar.br/oai/requestopendoar:43222023-09-18T18:31:14Repositório Institucional da UFSCAR - Universidade Federal de São Carlos (UFSCAR)false |
dc.title.por.fl_str_mv |
Mecanismos eletroquímicos nos processos de descarga do sistema PbO2/H2SO4 |
dc.title.alternative.eng.fl_str_mv |
Electrochemichal mechanisms in the discharge processes of PbO2/H2SO4 system |
title |
Mecanismos eletroquímicos nos processos de descarga do sistema PbO2/H2SO4 |
spellingShingle |
Mecanismos eletroquímicos nos processos de descarga do sistema PbO2/H2SO4 Freitas, Heverson Renan Baterias de chumbo-ácido Dióxido de chumbo Filmes de passivação Reação de estado sólido Placa positiva Lead-acid battery Lead dioxide Passivation films Solid state reactions Positive plate CIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICA::CINETICA QUIMICA E CATALISE CIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICA::ELETROQUIMICA CIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICA |
title_short |
Mecanismos eletroquímicos nos processos de descarga do sistema PbO2/H2SO4 |
title_full |
Mecanismos eletroquímicos nos processos de descarga do sistema PbO2/H2SO4 |
title_fullStr |
Mecanismos eletroquímicos nos processos de descarga do sistema PbO2/H2SO4 |
title_full_unstemmed |
Mecanismos eletroquímicos nos processos de descarga do sistema PbO2/H2SO4 |
title_sort |
Mecanismos eletroquímicos nos processos de descarga do sistema PbO2/H2SO4 |
author |
Freitas, Heverson Renan |
author_facet |
Freitas, Heverson Renan |
author_role |
author |
dc.contributor.authorlattes.por.fl_str_mv |
http://lattes.cnpq.br/8829870766609044 |
dc.contributor.author.fl_str_mv |
Freitas, Heverson Renan |
dc.contributor.advisor1.fl_str_mv |
D'Alkaine, Carlos Ventura |
dc.contributor.advisor1Lattes.fl_str_mv |
http://lattes.cnpq.br/8699821828310072 |
dc.contributor.authorID.fl_str_mv |
1bc084c5-2db5-4b94-b79c-625c01d6c2ca |
contributor_str_mv |
D'Alkaine, Carlos Ventura |
dc.subject.por.fl_str_mv |
Baterias de chumbo-ácido Dióxido de chumbo Filmes de passivação Reação de estado sólido Placa positiva |
topic |
Baterias de chumbo-ácido Dióxido de chumbo Filmes de passivação Reação de estado sólido Placa positiva Lead-acid battery Lead dioxide Passivation films Solid state reactions Positive plate CIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICA::CINETICA QUIMICA E CATALISE CIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICA::ELETROQUIMICA CIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICA |
dc.subject.eng.fl_str_mv |
Lead-acid battery Lead dioxide Passivation films Solid state reactions Positive plate |
dc.subject.cnpq.fl_str_mv |
CIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICA::CINETICA QUIMICA E CATALISE CIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICA::ELETROQUIMICA CIENCIAS EXATAS E DA TERRA::QUIMICA::FISICO-QUIMICA |
description |
The goal of this work was to seek a mechanistic and morphological understanding of the discharge process of lead-acid batteries’ positive plates, which exhibits a complex porous structure. Due to this fact, nonporous electrodes, ideally porous electrodes and positive plates were investigated. Studies on the discharge process of nonporous electrodes facilitated the reactional processes understanding from a mechanistic and morphological point of view. It was shown the existence of two steps during the discharge process. The first step is easily invertible and follows a solid state reaction mechanism, in which is possible to calculate the ionic resistivity evolution during the voltametric transient. The discharge product of the first step seems to be a PbOn1 electronic conductor (due to its stoichiometry) and, from the fact that it is a very thin film attached to the surface, this product was not observable by SEM measurements. On the other hand, the second step is not easily invertible and occurs at slower rates. During the second step, there is a stoichiometric change on the discharge product of the first step, giving rise to a PbOn2 (unstable and electronic insulator) that reacts with H2SO4 on the solution and forms lead basic sulfates. By the end of the second step, the discharge products give rise to structures observable by SEM measurements, which result from a dissolution/precipitation mechanism (that may occur due to longer processes times). The final stationary potential for discharge process of the PbO2/H2SO4 system was determined. Studies on ideally porous electrodes made it clear the existence of a zonal character of the discharge reactions. Studies on positive plates allowed the understanding of how complex the kinetic processes are on porous electrodes when compared to nonporous systems. Due to the structural complexity and the reactional zonal character, the transformations are much slower (time order of months). Besides that, the equilibrium O2/H2O must be taken into account to understand the results on positive plates, due to O2 bubbles trapped inside the pores during previous charge processes. These interpretations were made possible by Open Circuit Potential measurements assisted by concepts of Mixed Potential and Dynamical Systems Theories, specially the concept of attractor. This methodology allowed a new approach to electrochemical processes that implies multiple electrodes. |
publishDate |
2017 |
dc.date.issued.fl_str_mv |
2017-11-17 |
dc.date.accessioned.fl_str_mv |
2018-05-15T00:00:08Z |
dc.date.available.fl_str_mv |
2018-05-15T00:00:08Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/doctoralThesis |
format |
doctoralThesis |
status_str |
publishedVersion |
dc.identifier.citation.fl_str_mv |
FREITAS, Heverson Renan. Mecanismos eletroquímicos nos processos de descarga do sistema PbO2/H2SO4. 2017. Tese (Doutorado em Química) – Universidade Federal de São Carlos, São Carlos, 2017. Disponível em: https://repositorio.ufscar.br/handle/ufscar/10011. |
dc.identifier.uri.fl_str_mv |
https://repositorio.ufscar.br/handle/ufscar/10011 |
identifier_str_mv |
FREITAS, Heverson Renan. Mecanismos eletroquímicos nos processos de descarga do sistema PbO2/H2SO4. 2017. Tese (Doutorado em Química) – Universidade Federal de São Carlos, São Carlos, 2017. Disponível em: https://repositorio.ufscar.br/handle/ufscar/10011. |
url |
https://repositorio.ufscar.br/handle/ufscar/10011 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.relation.confidence.fl_str_mv |
600 600 |
dc.relation.authority.fl_str_mv |
143b0d3a-e240-4428-9335-3a5c32e5bfeb |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.publisher.none.fl_str_mv |
Universidade Federal de São Carlos Câmpus São Carlos |
dc.publisher.program.fl_str_mv |
Programa de Pós-Graduação em Química - PPGQ |
dc.publisher.initials.fl_str_mv |
UFSCar |
publisher.none.fl_str_mv |
Universidade Federal de São Carlos Câmpus São Carlos |
dc.source.none.fl_str_mv |
reponame:Repositório Institucional da UFSCAR instname:Universidade Federal de São Carlos (UFSCAR) instacron:UFSCAR |
instname_str |
Universidade Federal de São Carlos (UFSCAR) |
instacron_str |
UFSCAR |
institution |
UFSCAR |
reponame_str |
Repositório Institucional da UFSCAR |
collection |
Repositório Institucional da UFSCAR |
bitstream.url.fl_str_mv |
https://repositorio.ufscar.br/bitstream/ufscar/10011/4/license.txt https://repositorio.ufscar.br/bitstream/ufscar/10011/5/FREITAS_Heverson_2018.pdf https://repositorio.ufscar.br/bitstream/ufscar/10011/6/FREITAS_Heverson_2018.pdf.txt https://repositorio.ufscar.br/bitstream/ufscar/10011/7/FREITAS_Heverson_2018.pdf.jpg |
bitstream.checksum.fl_str_mv |
ae0398b6f8b235e40ad82cba6c50031d e4f084c40f6857f77515e94fc1ed7053 32608b62187347a37c023120e26f4d00 a0fd8d31a348b6074a6e8037ff7addb5 |
bitstream.checksumAlgorithm.fl_str_mv |
MD5 MD5 MD5 MD5 |
repository.name.fl_str_mv |
Repositório Institucional da UFSCAR - Universidade Federal de São Carlos (UFSCAR) |
repository.mail.fl_str_mv |
|
_version_ |
1802136340123353088 |