Study of the mechanisms of O2-reduction and degradation operating on La0.5-XPrxBa0.5CoO3-δ cathodes for SOFCs

D. Garcés, H. Wang, S. A. Barnett, A. G. Leyva, L. V. Mogni

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Scopus citations

Abstract

The oxygen reduction mechanism and time evolution behavior were studied for porous La0.5-xPrxBa0.5CoO3-δ (LPBC) electrodes deposited onto Ce0.9Gd0.1O1.95 electrolytes. Electrochemical impedance spectroscopy (EIS) measurements, performed between 400 and 800°C as a function of pO2, show that the electrochemical response is limited by O2-gas diffusion and surface reaction (Osurface exchange + O-ion diffusion). The time evolution of the cathode resistance at 700°C in air shows an increase from 0.03 to 0.05 Ωcm2 after 280 h of testing. Three-dimensional (3D) tomographic using focused ion beam-scanning electron microscopy (FIB-SEM) showed little changes of microstructure after the ageing. The increase in resistance was explained by an increase in the amount of a water-soluble Ba-rich surface phase by a factor of 2, after ageing of the LPBC electrode, by an etching procedure coupled with inductively coupled plasma-optical emission spectrometry (ICP-OES).

Original languageEnglish (US)
Title of host publicationECS Transactions
EditorsS. C. Singhal, T. Kawada
PublisherElectrochemical Society Inc.
Pages1011-1020
Number of pages10
Edition1
ISBN (Electronic)9781607688150, 9781607688150
DOIs
StatePublished - May 30 2017
Event15th International Symposium on Solid Oxide Fuel Cells, SOFC 2017 - Hollywood, United States
Duration: Jul 23 2017Jul 28 2017

Publication series

NameECS Transactions
Number1
Volume78
ISSN (Print)1938-6737
ISSN (Electronic)1938-5862

Other

Other15th International Symposium on Solid Oxide Fuel Cells, SOFC 2017
Country/TerritoryUnited States
CityHollywood
Period7/23/177/28/17

ASJC Scopus subject areas

  • Engineering(all)

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