Development of bilayer glass-ceramic SOFC sealants via optimizing the chemical composition of glasses-a review
authors Reddy, AA; Tulyaganov, DU; Kharton, VV; Ferreira, JMF
nationality International
journal JOURNAL OF SOLID STATE ELECTROCHEMISTRY
keywords OXIDE FUEL-CELLS; MOLECULAR-DYNAMICS SIMULATION; SYSTEMS RO-BAO-SIO2 R; SILICATE-GLASSES; LA2O3-NA2O-SIO2 GLASSES; ALUMINOBOROSILICATE GLASS; CRYSTALLIZATION KINETICS; ELECTRICAL BEHAVIOR; SINTERING BEHAVIOR; THERMAL-PROPERTIES
abstract Glasses and glass-ceramics (GCs), in particular alkaline-earth alumino silicate-based compositions, are becoming the most common sealing materials for gas-tight sealing applications in solid oxide fuel cells (SOFCs). The present review aims at reporting the systematic procedures put forward developing a novel concept of diopside-based bilayer GC seal, which contains a rigid GC and a self-healing (SH) GC. The concept behind the bilayer GCs is (i) a small gradient in the coefficient of thermal expansion (CTE) will lead to lower thermal expansion mismatch between the sealing layers and other SOFC components, thus providing enhanced mechanical reliability for the stack; and (ii) cracks produced due to minor thermal stresses in the rigid GC layer can be healed by the SH GC layer due to sufficient amorphous content. In general, at high temperature, highly crystallized glass behaves as a rigid glass. On the other hand, due to low viscosity behavior, partially crystallized glass provides a SH behavior. Various glasses in the field of diopside crystalline materials have been systematically designed by varying the chemical composition of glass to achieve desired combination of functional properties for the rigid and SH GC layers. The glass Sr-0.3 where Sr replaced 30 % of Ca was revealed as a highly reliable rigid GC seal for high-temperature electrochemical applications. On the other hand, SH features have been achieved in 30 % Sr-containing diopside-based glass with Gd2O3 for MgO + SiO2 substitution (denoted as Gd-0.3). These GCs exhibit similar thermal properties and excellent thermal stability along a period of 1000 h, while differing in their amorphous fractions, and revealed excellent thermal stability along a period of 1000 h. The bilayered GC synthesized from Sr-0.3 and Gd-0.3 showed good wetting and bonding ability to the SOFC metallic Crofer22APU components. The results revealed superior performance for the newly proposed bilayer GCs in comparison to single-layer sealants.
publisher SPRINGER
issn 1432-8488
year published 2015
volume 19
issue 10
beginning page 2899
ending page 2916
digital object identifier (doi) 10.1007/s10008-015-2925-5
web of science category Electrochemistry
subject category Electrochemistry
unique article identifier WOS:000362335900002
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journal analysis (jcr 2017):
journal impact factor 2.509
5 year journal impact factor 2.348
category normalized journal impact factor percentile 51.786
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