New glass and glass-ceramic sealants for planar solid oxide fuel cells

This work describes the design of three new glass and glass ceramic compositions to join the ceramic electrolyte (YSZ wafer) to the metallic interconnect (Crofer22APU) in planar SOFC stacks. The designed sealants are low-sodium, barium free and boron-oxide free silica-based glasses. The sealing process was optimized for the most promising composition and joined Crofer22APU/glass-ceramic sealant/YSZ samples were morphologically characterized and tested for 300 h in humidified hydrogen atmosphere at the fuel cell operating temperature of 800 degrees C. The study showed that the use of the glass-ceramic was successful in joining the YSZ ceramic electrolyte to the Crofer22APU metallic interconnect and in preventing severe corrosion effects at the Crofer22APU/glass-ceramic interface after static treatments in humidified hydrogen at 800 degrees C for 300 h. (C) 2009 Elsevier Ltd. All rights reserved.