abstract
Development of the cathode contact materials (CCMs) for intermediate-temperature solid oxide fuel cells (IT-SOFCs) is a relatively new task promoted by the appearance of full-sized cells, which may operate below 700 degrees C with sufficient performance, on the market. CCM must ensure a low-resistive interface between interconnect and cathode and is supposed to be sintered at temperatures below 800 degrees C, as imposed by the specifications of IT-SOFCs and corresponding sealants. The present work is focused on the elaboration of CCMs derived from perovskite-like La0.6Sr0.4Co0.2Fe0.8O3-delta employing two approaches: introduction of the A-site cation vacancies and partial substitution by copper in B sublattice. Both approaches were found to result in a higher electrical conductivity below 800 degrees C if compared to the parent material. All studied materials exhibit acceptable coefficients of thermal expansion, 13.5-14.8 ppm K-1 at 25-700 degrees C. Area-specific resistance (ASR) of CCM/chromium barrier (Mn1.5Co1.5O4)/interconnect (Crofer 22APU) assemblies prepared by the screen-printing was measured in air at 660-750 degrees C. The studies revealed that morphology of CCM powder should be considered as a key parameter in the formation of interfaces with a low resistivity. The best ASR values, below 4 m Omega cm(2) at 660-700 degrees C, were obtained for La0.6Sr0.4Co0.15Cu0.10Fe0.75O3-delta, La0.6Sr0.4Co0.15Cu0.05Fe0.80O3-delta and (La0.60Sr0.40)(0.995)Co-0.20 Fe0.80O3-delta as CCMs. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
keywords
ELECTROCHEMICAL PERFORMANCE; (LA,SR)(CO,FE)O-3 CATHODES; METALLIC INTERCONNECT; CHROMIUM DEPOSITION; SPINEL COATINGS; PEROVSKITES; LAYERS; LANI0.6FE0.4O3; EXPANSION; ENERGY
subject category
Chemistry; Electrochemistry; Energy & Fuels
authors
Naumouich, EN; Zakharchuk, K; Obrebowski, S; Yaremchenko, A
our authors
Aleksey Yaremchenko
Principal Researcher
Kiryl Zakharchuk
PhD StudentProjects
acknowledgements
E.N. Naumovich and S. Obrqbowski would like to acknowledge financial support from the Polish Ministry of Higher Education and Science statutory program, grant no. CPC/4/STAT/2016. K. Zakharchuk and A. Yaremchenko would like to acknowledge financial support from the FCT, Portugal (project IF/01072/2013/CP1162/CT0001 and project CICECO - Aveiro Institute of Materials POCI-01-0145-FEDER-007679 (FCT ref. UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement).