A New Sealant Material for Solid Oxide Fuel Cells Using Glass-Ceramic

摘要

We report a new sealant material for solid oxide fuel cells (SOFCs) using glass-ceramic. A glass-ceramic based on the CaO-Al_2O_3-SiO_2 system was selected as a sealant because it can be easily molded to give a gas-tight seal and remains in a solid-like state under typical fuel cell operating conditions. Calcium alumina silicate glass powder is placed in the gas-sealing area before crystallization. During heating, the glass softens and bonds with the SOFC components. At higher temperatures, bulk crystallization occurs in the glass and the viscosity of the glass-ceramic sealant increases. We show that this sealing material which is able to seal at higher viscosities compared with the melt sealing method produces a good gas-tight seal and is chemically stable in contact with SOFC components, e.g., yttria-stabilized zirconia electrolytes and lanthanum chromite separators.