abstract
Calcium cobaltites have emerged as an attractive alternative to be used in Solid Oxide Cells (SOCs), due to their excellent thermal compatibility with standard electrolytes that may privilege these compounds among state-of-the-art SOC electrodes. Nonetheless, their electrochemical performances have been strongly limited by poor oxygen ion transport. Hence, we report a new composite electrode containing the misfit calcium cobaltite [Ca2CoO3-delta](0.62)[CoO2] (C349) phase combined with Ce0.8Pr0.2O2-delta (CPO). A comparative study is presented between this composite and the standard La0.6Sr0.4Co0.2Fe0.8O3-delta (LSCF), in terms of their microstructures, number of depositions, and resultant electrochemical properties. Such tailoring permits the best C349/CPO composite electrode to attain high levels of electrochemical performance that rival with the standard LSCF material. This successful result is highly relevant, as it can provide insight into the most critical optimisation factors for similar SOC electrodes that intrinsically suffer from similarly low levels of ionic transport. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
keywords
MISFIT-LAYERED COBALTITE; ELECTROCHEMICAL PERFORMANCE; THERMAL-EXPANSION; RELAXATION-TIMES; LA0.6SR0.4CO0.2FE0.8O3-DELTA CATHODES; HYDROTHERMAL SYNTHESIS; TRANSPORT-PROPERTIES; MODULATED STRUCTURE; MIXED CONDUCTIVITY; REDUCTION REACTION
subject category
Chemistry, Physical; Electrochemistry; Energy & Fuels
authors
Araujo, AJM; Loureiro, FJA; Holz, LIV; Grilo, JPF; Macedo, DA; Paskocimas, CA; Fagg, DP
our authors
Francisco José Almeida Loureiro
Research Fellowship
João Paulo de Freitas Grilo
Junior Researcheracknowledgements
This study was financed in part by the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior - Brasil (CAPES) - Finance Code 001. Allan J. M. Araujo thanks the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq/Brazil, reference number 200439/2019-7). Joao P. F. Grilo, Carlos A. Paskocimas and Daniel A. Macedo also thank CNPq/Brazil (482473/2010-0, 446126/2014-4, 308548/2014-0, 307236/2018e8, 431428/2018-2 and 309430/2019-4). The Aveiro team acknowledges projects PTDC/CTM-CTM/2156/2020, POCI-010145-FEDER-032241, UID/EMS/00481/2019-FCT, CENTRO-010145-FEDER-022083, funded by FEDER, Centro Portugal Regional Operational Programme (Centro2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) and by national funds (OE), through FCT/MCTES.