resumo
A series of alkaline-earth aluminosilicate glass-ceramics (GCs) were appraised with respect to their suitability as sealants for solid oxide fuel cells (SOFCs). The parent composition with general formula Ca(0.9)MgAl(0.1)La(0.1)Si(1.9)O(6) was modified with Cr(2)O(3) and BaO. The addition of BaO led to a substantial decrease in the total electrical conductivity of the GCs, thus improving their insulating properties. BaO-containing GCs exhibited higher coefficient of thermal expansion (CTE) in comparison to BaO-free GCs. An extensive segregation of oxides of Ti and Mn, components of the Crofer22 APU interconnect alloy, along with negligible formation of BaCrO(4) was observed at the interface between GC/interconnects diffusion couples. Thermal shock resistance and gas-tightness of GC sealants in contact with yttria-stabilized zirconia electrolyte (8YSZ) was evaluated in air and water. Good matching of CTE and strong, but not reactive, adhesion to the solid electrolyte and interconnect, in conjunction with a high level of electrical resistivity, are all advantageous for potential SOFC applications. (C) 2009 Elsevier B. V. All rights reserved.
palavras-chave
CRYSTALLIZATION
categoria
Chemistry; Electrochemistry; Energy & Fuels; Materials Science
autores
Goel, A; Tulyaganov, DU; Kharton, VV; Yaremchenko, AA; Ferreira, JMF
nossos autores
Aleksey Yaremchenko
Investigador Principal
José Maria da Fonte Ferreira
Professor(a) Jubilado(a)
Vladislav Kharton
Investigador Principal CovidadoGrupos
G3 - Materiais Eletroquímicos, Interfaces e Revestimentos
G5 - Materiais Biomiméticos, Biológicos e Vivos
agradecimentos
This study was financially supported by University of Aveiro, CICECO and FCT, Portugal (SFRH/BD/37037/2007).