Behavior of (La,Sr)CoO3- and La2NiO4-based ceramic anodes in alkaline media: compositional and microstructural factors

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dc.contributor.authorPoznyak, SKen_AU
dc.contributor.authorKharton, VVen_AU
dc.contributor.authorFrade, JRen_AU
dc.contributor.authorYaremchenko, AAen_AU
dc.contributor.authorTsipis, EVen_AU
dc.contributor.authorYakovlev, SOen_AU
dc.contributor.authorMarozau, IPen_AU
dc.date.accessioned2009-10-06T04:39:35Zen_AU
dc.date.accessioned2010-04-30T05:03:16Zen_AU
dc.date.available2009-10-06T04:39:35Zen_AU
dc.date.available2010-04-30T05:03:16Zen_AU
dc.date.issued2008-01en_AU
dc.date.statistics2008-01en_AU
dc.description.abstractThe behavior of dense ceramic anodes made of perovskite-type La1-x-ySrxCo1-zAlzO3-δ (x=0.30-0.70; y=0-0.05; z=0-0.20) and K2NiF4- type La2Ni1-xMexO4+δ (Me=Co, Cu; x=0-0.20) indicates significant influence of metal hydroxide formation at the electrode surface on the oxygen evolution reaction (OER) kinetics in alkaline solutions. The overpotential of cobaltite electrodes was found to decrease with time, while cyclic voltammetry shows the appearance of redox peaks characteristic of Co(OH)(2)/CoOOH. This is accompanied with increasing effective capacitance estimated from the impedance spectroscopy data, because of roughening of the ceramic surface. The steady-state polarization curves of (La,Sr)CoO3-δ in the OER range, including the Tafel slope, are very similar to those of model Co(OH)(2)-La(OH)(3) composite films where the introduction of lanthanum hydroxide leads to decreasing electrochemical activity. La2NiO4-based anodes exhibit a low electrochemical performance and poor stability. The effects of oxygen nonstoichiometry of the perovskite-related phases are rather negligible at high overpotentials but become significant when the polarization decreases, a result of increasing role of oxygen intercalation processes. The maximum electrocatalytic activity to OER was observed for A-site-deficient (La0.3Sr0.7)(0.97)CoO3-δ, where the lanthanum content is relatively low and the Co4+ concentration determined by thermogravimetric analysis is highest compared to other cobaltites. Applying microporous layers made of template-synthesized nanocrystalline (La0.3Sr0.7)(0.97)CoO3-δ leads to an improved anode performance, although the effects of microstructure and thickness are modest, suggesting a narrow electrochemical reaction zone. Further enhancement of the OER kinetics can be achieved by electrodeposition of cobalt hydroxide- and nickel hydroxide- based films. © 2008, Springer.en_AU
dc.identifier.citationPoznyak, S. K., Kharton, V. V., Frade, J. R., Yaremchenko, A. A., Tsipis, E. V., Yakovlev, S. O., & Marozau, I. P. (2008). Behavior of (La,Sr)CoO3- and La2NiO4-based ceramic anodes in alkaline media: compositional and microstructural factors. Journal of Solid State Electrochemistry, 12(1), 15-30. doi:10.1007/s10008-007-0353-xen_AU
dc.identifier.govdoc1211en_AU
dc.identifier.issn1432-8488en_AU
dc.identifier.issue1en_AU
dc.identifier.journaltitleJournal of Solid State Electrochemistryen_AU
dc.identifier.pagination15-30en_AU
dc.identifier.urihttp://dx.doi.org/10.1007/s10008-007-0353-xen_AU
dc.identifier.urihttp://apo.ansto.gov.au/dspace/handle/10238/1933en_AU
dc.identifier.volume12en_AU
dc.language.isoenen_AU
dc.publisherSpringeren_AU
dc.subjectAnodesen_AU
dc.subjectLanthanumen_AU
dc.subjectPerovskitesen_AU
dc.subjectOxygenen_AU
dc.subjectElectrodesen_AU
dc.subjectHydroxidesen_AU
dc.titleBehavior of (La,Sr)CoO3- and La2NiO4-based ceramic anodes in alkaline media: compositional and microstructural factorsen_AU
dc.typeJournal Articleen_AU
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