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Effect of temperature on structure and electronic properties of nanometric spinel-type cobalt oxides

hal.structure.identifierInstitut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
dc.contributor.authorGODILLOT, Gérôme
hal.structure.identifierInstitut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
dc.contributor.authorGUERLOU-DEMOURGUES, Liliane
hal.structure.identifierInstitut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
dc.contributor.authorCROGUENNEC, Laurence
hal.structure.identifierInstitut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
dc.contributor.authorSHAJU, K. M.
hal.structure.identifierInstitut de Chimie de la Matière Condensée de Bordeaux [ICMCB]
dc.contributor.authorDELMAS, Claude
dc.date.issued2013
dc.identifier.issn1932-7447
dc.description.abstractEnTemperature is shown to have a huge influence on the electronic properties of nanometric spinel-type cobalt oxides precipitated at low temperature in alkaline media. The initial phase, with formula HxLiyCo3−δO4, contains hydrogen, lithium, cobalt vacancies, and a mixed valence Co4+/Co3+ within the structure, leading to an electronic conductivity higher than that of stoichiometric Co3O4. Its structural evolution under thermal treatment was studied by X-ray diffraction and chemical analysis, which reveal modifications in structure and compositions, involving water release, increase of the Co/O atomic ratio, and modification of the Co4+/Co3+ ratio. The RT to 300 °C range is particularly interesting as a single-phase domain and the materials obtained in this temperature range were investigated by chemical analysis, electronic conductivity and specific surface area measurements. Upon increasing temperature, the enhancement of the Co4+/Co3+ ratio, together with cationic redistribution in the spinel framework, results in an improvement of the electronic conductivity (more than 2 orders of magnitude for materials heated above 150 °C). Finally, the systematic thermal study of electronic conductivity and specific surface area of the materials allows to determine an optimal heat-treatment temperature leading to an optimized active electrode material for electrochemical energy storage applications, especially in supercapacitors. Such a solid state chemistry approach combining many material characterization techniques to reach a complete knowledge of the material is quite rare in the literature concerning oxides for supercapacitors.
dc.language.isoen
dc.publisherAmerican Chemical Society
dc.title.enEffect of temperature on structure and electronic properties of nanometric spinel-type cobalt oxides
dc.typeArticle de revue
dc.identifier.doi10.1021/jp3100359
dc.subject.halChimie/Matériaux
bordeaux.journalJournal of Physical Chemistry C
bordeaux.page9065-9075
bordeaux.volume117
bordeaux.issue18
bordeaux.peerReviewedoui
hal.identifierhal-00828061
hal.version1
hal.popularnon
hal.audienceInternationale
dc.subject.esCobalt Oxides
dc.subject.esNanoparticles
dc.subject.esSpinel
dc.subject.esPhysical properties
hal.origin.linkhttps://hal.archives-ouvertes.fr//hal-00828061v1
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