abstract
The electrochemical, transport and thermomechanical properties of perovskite-type (La-1 (-) Sr-x(x))(1 - y)Mn0.5Ti0.5O3 (-) (delta) (x = 0.15-0.75; y = 0-0.05), (La0.75 - xSr0.25 + x)(0.95)Mn0.5Cr0.5 - xTixO3 - delta (x = 00.5), (La0.75Sr0.25)(0.95)Cr1 - xFexO3 (- delta) (x = 0.3-0.4), SrNb1 - xMnxO3 - delta (x = 0.50.8) and (La0.9Sr0.1)(0.95)Cr0.85Mg0.1Ni0.05O3 - delta have been appraised in light of their applicability for solid oxide fuel cell (SOFC) anodes. The electrical conductivity, measured in the oxygen partial pressure range of 10(-20) to 0.5 atm at 940-1270 K, increases with manganese and strontium additions which lead, however, to higher reducibility. In addition to the thermodynamic stability limitations under the SOFC anodic conditions, the latter factor raises the importance of chemically induced expansion, as for Fe-substituted (La,Sr)CrO3 (- delta). The reduction of Ni-doped chromite results in the formation of nanosized metallic particles dispersed on the perovskite surface, and has no significant effect on the transport properties governed by the perovskite phase. The maximum electrochemical performance was observed for porous La0.5Sr0.5Mn0.5Ti0.5O3 - delta, (La0.9Sr0.1)(0.95)Cr0.85Mg0.1Ni0.05O3 - delta and (La0.75Sr0.25)(0.95)Cr0.7Fe0.3O3 - delta electrodes in the electrochemical cells with lanthanum gallate-based solid electrolyte and Ce0.8Gd0.2O2 - delta interlayers. (C) 2013 Elsevier B.V. All rights reserved.
keywords
OXIDE FUEL-CELLS; ELECTROCHEMICAL-BEHAVIOR; TRANSPORT; CONDUCTIVITY; ELECTROLYTE; CATHODES
subject category
Chemistry; Physics
authors
Kolotygin, VA; Tsipis, EV; Lu, MF; Pivak, YV; Yarmolenko, SN; Bredikhin, SI; Kharton, VV
our authors
Vladislav Kharton
Invited Principal ResearcherGroups
Projects
Centre for Research in Ceramics and Composite Materials - CICECO (LA0011: 2011-2012) (PEst-C/CTM/LA0011/2011)
Novel methodological approaches to analyze ion transport mechanism in complex crystal lattices and to forecast performance-determining parameters of the oxide materials (PTDC/CTM-CER/114561/2009)
acknowledgements
This work was supported by FCT, Portugal (projects PEst-C/CTM/LA0011/2011, PTDC/CTM-CER/114561/2009, SFRH/BPD/28629/2006 and SFRH/BD/45227/2008), by the Ministry of Education and Science of the Russian Federation (state contracts 02.740.11.5214 and 11.519.11.6002), and by the NSF, USA (project DMR-0502765). Experimental assistance and helpful discussions made by A. Ivanov, A. Yaremchenko and A. Shaula are gratefully acknowledged.