Transport properties and electrochemical activity of YBa(Co,Fe)(4)O-7 cathodes
authors Tsipis, EV; Kharton, VV; Frade, JR
nationality International
journal SOLID STATE IONICS
author keywords yttrium-barium cobaltite; SOFC cathode; oxygen stoichiometry; phase transition; transference number
abstract The layered phases derived from YBaCo4O7 exhibit a relatively low thermal expansion, significant mixed conductivity and attractive electrochemical activity in contact with doped LaGaO3 solid electrolyte. These properties may be of interest for intermediate-temperature SOFC cathodes. Moderate doping of yttrium-barium cobaltite with iron decreases slightly the total conductivity, predominantly p-type electronic, and have no essential effect on the oxygen ion transport and cathodic polarization at 1073 K. However, hexagonal YBaCo4O7, where the average cobalt oxidation state is +2.25, and its derivatives appear metastable at temperatures below 1050-1100 K. Oxygen uptake at intermediate temperatures in air leads to the phase decomposition, accompanied by increasing conductivity and dramatic volume contraction. (c) 2006 Elsevier B.V. All rights reserved.
publisher ELSEVIER SCIENCE BV
issn 0167-2738
year published 2006
volume 177
issue 19-25
beginning page 1823
ending page 1826
digital object identifier (doi) 10.1016/j.ssi.2006.03.037
web of science category Chemistry, Physical; Physics, Condensed Matter
subject category Chemistry; Physics
unique article identifier WOS:000242555200053
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journal analysis (jcr 2019):
journal impact factor 3.107
5 year journal impact factor 2.904
category normalized journal impact factor percentile 58.409
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