Characterization and performance of glass-ceramic sealant to join metallic interconnects to YSZ and anode-supported-electrolyte in planar SOFCs

This work describes the design, development and performance of a glass-ceramic sealant used to join the ceramic electrolyte (YSZ wafer and anode-supported-electrolyte (ASE)) to the metallic interconnects (Crofer22 APU and AISI430) in planar SOFC stacks. The designed glass-ceramic sealant is a barium-free silica-based glass, which crystallizes by means of the heat treatment after being deposited on substrates by the slurry technique. The sealing process of the glass-ceramic was optimized and joined ceramic/seal/metal samples were morphologically characterized and tested for 400 It in air atmosphere followed by 200 h in H-2-3H(2)O 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 ceramic electrolyte to the metallic interconnect and in preventing adverse corrosion effects at the interface.