Properties of Glass-ceramic Seals for Solid Oxide Fuel Cells
The thermal stability of invert glass-ceramics, based on crystalline pyro- and orthosilicate phases, developed for hermetic seals for solid oxide fuel cells (SOFC) are described. The effects of long-term (up to 60 days) high temperature (up to 800°C) heat treatments on the properties of the glass-ceramics in oxidizing and reducing environments were evaluated by dilatometric analyses, x-ray diffraction, weight loss measurements, and impedance spectroscopy. The glass-ceramics have thermal expansion coefficients in the range 9.5-11.5 × 10-6/°C and can be sealed to SOFC materials, including Y2O3-stabilized ZrO2 (YSZ) and Cr-steel interconnect alloys, at or below 900°C. The thermal expansion characteristics of some glassceramics remain essentially unchanged after >40 days at 800°C, and the glass conductivity at 750°C remains constant (in the range 0.3-1.0 × 10-7 S/cm) in forming gas.
S. T. Reis et al., "Properties of Glass-ceramic Seals for Solid Oxide Fuel Cells," Advances in Solid Oxide Fuel Cells II: Ceramic Engineering and Science Proceedings, American Ceramic Society, Mar 2008.
The definitive version is available at http://dx.doi.org/10.1002/9780470291337.ch29
Materials Science and Engineering
Keywords and Phrases
Environments; Hermetic; Orthosilicate; Thermal; Platinum
Article - Conference proceedings
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