The role of the electric conductivity of carbons in the electrochemical capacitor performance

The interpretation of the performance of electrochemical capacitors based exclusively on the textural features and surface chemistry of carbons can be insufficient, or even misleading, in the case of materials prepared at low temperatures (typically below 800 °C). It is suggested that the gradual im...

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Detalles Bibliográficos
Autores: Sánchez González, José, Stoeckli, Fritz, Álvarez Centeno, Teresa
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2011
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/100226
Acceso en línea:http://hdl.handle.net/10261/100226
Access Level:acceso abierto
Palabra clave:Activated carbon
Heat-treatment
Electric conductivity
Electrochemical capacitor
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spelling The role of the electric conductivity of carbons in the electrochemical capacitor performanceSánchez González, JoséStoeckli, FritzÁlvarez Centeno, TeresaActivated carbonHeat-treatmentElectric conductivityElectrochemical capacitorThe interpretation of the performance of electrochemical capacitors based exclusively on the textural features and surface chemistry of carbons can be insufficient, or even misleading, in the case of materials prepared at low temperatures (typically below 800 °C). It is suggested that the gradual improvement of the electrochemical performances of carbon-based capacitors at high current densities, following heat treatments up to 900 °C, is mainly a consequence of the simultaneous increase in conductivity. This is illustrated by a study of carbons based on a mesoporous carbon prepared at 550 °C, which displays poor electrochemical performances and a low conductivity (4.6 × 10−6 S m−1). A first heat treatment at 700 °C leads to major structural, chemical and electrochemical changes, due to the collapse of the smaller mesopores and the formation of a microporous structure with average pore widths around 1.3 nm. One also observes a reduction in the surface oxygen density from 13 to approximately 5 μmol m−2. Further heat treatments at 800 and 900 °C do not modify significantly these characteristics, nor the surface-related capacitances at low current densities (1 mA cm−2) in the aqueous (2 M H2SO4) and organic (1 M (C2H5)4NBF4/CH3CN) electrolytes. On the other hand, one observes increasingly high rate capabilities which may be ascribed to the simultaneous increase in conductivity from 7.3 to 147.8 S m−1 between 700 and 900 °C.The authors wish to thank Dr. F. Rubiera and Dr. C. Pevida for the gift of carbons and Dr. J.A.Fernández for some electrochemical measurements.Peer reviewedElsevierConsejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]201420142011info:eu-repo/semantics/articlehttp://purl.org/coar/resource_type/c_6501Postprintinfo:eu-repo/semantics/acceptedVersionhttp://hdl.handle.net/10261/100226reponame:DIGITAL.CSIC. Repositorio Institucional del CSICinstname:Consejo Superior de Investigaciones Científicas (CSIC)Ingléshttp://dx.doi.org/10.1016/j.jelechem.2011.03.025Síinfo:eu-repo/semantics/openAccessoai:digital.csic.es:10261/1002262026-05-22T06:33:51Z
dc.title.none.fl_str_mv The role of the electric conductivity of carbons in the electrochemical capacitor performance
title The role of the electric conductivity of carbons in the electrochemical capacitor performance
spellingShingle The role of the electric conductivity of carbons in the electrochemical capacitor performance
Sánchez González, José
Activated carbon
Heat-treatment
Electric conductivity
Electrochemical capacitor
title_short The role of the electric conductivity of carbons in the electrochemical capacitor performance
title_full The role of the electric conductivity of carbons in the electrochemical capacitor performance
title_fullStr The role of the electric conductivity of carbons in the electrochemical capacitor performance
title_full_unstemmed The role of the electric conductivity of carbons in the electrochemical capacitor performance
title_sort The role of the electric conductivity of carbons in the electrochemical capacitor performance
dc.creator.none.fl_str_mv Sánchez González, José
Stoeckli, Fritz
Álvarez Centeno, Teresa
author Sánchez González, José
author_facet Sánchez González, José
Stoeckli, Fritz
Álvarez Centeno, Teresa
author_role author
author2 Stoeckli, Fritz
Álvarez Centeno, Teresa
author2_role author
author
dc.contributor.none.fl_str_mv Consejo Superior de Investigaciones Científicas [https://ror.org/02gfc7t72]
dc.subject.none.fl_str_mv Activated carbon
Heat-treatment
Electric conductivity
Electrochemical capacitor
topic Activated carbon
Heat-treatment
Electric conductivity
Electrochemical capacitor
description The interpretation of the performance of electrochemical capacitors based exclusively on the textural features and surface chemistry of carbons can be insufficient, or even misleading, in the case of materials prepared at low temperatures (typically below 800 °C). It is suggested that the gradual improvement of the electrochemical performances of carbon-based capacitors at high current densities, following heat treatments up to 900 °C, is mainly a consequence of the simultaneous increase in conductivity. This is illustrated by a study of carbons based on a mesoporous carbon prepared at 550 °C, which displays poor electrochemical performances and a low conductivity (4.6 × 10−6 S m−1). A first heat treatment at 700 °C leads to major structural, chemical and electrochemical changes, due to the collapse of the smaller mesopores and the formation of a microporous structure with average pore widths around 1.3 nm. One also observes a reduction in the surface oxygen density from 13 to approximately 5 μmol m−2. Further heat treatments at 800 and 900 °C do not modify significantly these characteristics, nor the surface-related capacitances at low current densities (1 mA cm−2) in the aqueous (2 M H2SO4) and organic (1 M (C2H5)4NBF4/CH3CN) electrolytes. On the other hand, one observes increasingly high rate capabilities which may be ascribed to the simultaneous increase in conductivity from 7.3 to 147.8 S m−1 between 700 and 900 °C.
publishDate 2011
dc.date.none.fl_str_mv 2011
2014
2014
dc.type.none.fl_str_mv info:eu-repo/semantics/article
http://purl.org/coar/resource_type/c_6501
Postprint
info:eu-repo/semantics/acceptedVersion
format article
status_str acceptedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/10261/100226
url http://hdl.handle.net/10261/100226
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv http://dx.doi.org/10.1016/j.jelechem.2011.03.025
Sí
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.publisher.none.fl_str_mv Elsevier
publisher.none.fl_str_mv Elsevier
dc.source.none.fl_str_mv reponame:DIGITAL.CSIC. Repositorio Institucional del CSIC
instname:Consejo Superior de Investigaciones Científicas (CSIC)
instname_str Consejo Superior de Investigaciones Científicas (CSIC)
reponame_str DIGITAL.CSIC. Repositorio Institucional del CSIC
collection DIGITAL.CSIC. Repositorio Institucional del CSIC
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15.81155

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