Oxygen permeation in bismuth-based materials part I: Sintering and oxygen permeation fluxes

Oxygen permeation measurements were performed on two layered bismuth based oxide ceramics: a rhombohedral phase belonging to the Bi2O3-CaO system, (Bi2O3)0.73- (CaO)0.27 (BICAO) and a BICOVOX phase. Oxygen permeability for these systems was compared to permeability of the cubic fluorite type structure with composition (Bi2O3)0.75(Er2O3)0.25 (BE25). Low oxygen permeability was observed for the pure ceramic. As for BE25, permeability was considerably increased if 40 vol% of silver was added to BICAO. In contrast, permeability was not improved by addition of gold to BICOVOX. For this latter phase, the oxygen molecular exchange at the surface is clearly the limiting step in the oxygen transfer

Impact of the strontium content on the performance of ESB/LSM composite electrodes for low temperature SOFCs

International audienc

Influence of the transport mechanism on the performance of ESB-LSM composite cathode for LT-SOFCs

National audienc

Cathode Material Screening for SOFC Based on Stabilized Bi2O3 Electrolytes

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Impact of the Sr-content on nthe performance of ESB-LSM composite electrodes for LT-SOFCs

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Characterization of new cathodes materials for bismuth-based SOFC

National audienc

Research of innovative SOFC cathode materials

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Développement d’électrodes innovantes pour piles à combustible réalisées sur support métallique poreux

National audienc

Influence of the strontium content on the performance of La1-xSrxMnO3/Bi1.5Er0.5O3 composite electrodes for low temperature Solid Oxide Fuel Cells

International audienceThe possibility to use bilayer electrolytes based on bismuth oxide conductors should lead to a drastic decrease of solid oxide fuel cell (SOFC) operation temperature and calls for a reevaluation of some of the parameters optimized for high temperature applications. In this work we reinvestigate the promising La1-xSrxMnO3/Bi1.5Er0.5O3 (LSM/ESB) composite electrodes, varying the strontium content from x ~ 0.2, the typical high temperature LSM composition, to evaluate the optimum composition. Increasing the strontium content up to x 1⁄40.4–0.5 leads to a 14% decrease of the activation energy, resulting in a 50% decrease in the polarization resistance of symmetric cells at 500 °C compared to the traditional La0.85Sr0.15MnO3 composition with similar microstructure. The electrode performance is deteriorated by further increase in the strontium content. Based on surface composition, investigated by low energy ion scattering, we show that the SrO surface segregation pro­posed as the main deterioration mechanism for LSM based HT-SOFC is not an issue below 800 °C. Furthermore, we propose that the increase in performance is related to the decrease of cationic vacancies in LSM observed for high strontium content, which may help the oxygen dissociation and surface transport

La substituted Sr2MnO4 as candidate for symmetrical electrode for SOFC

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