Interaction study of yttria-based glasses with high-temperature electrolyte for SOFC

The chemical interaction study of AO-SiO₂-B₂O ₃-Y₂O₃ (A=Ba, Sr) (BaY, SrY) glass with high-temperature electrolyte yttria-stabilized zirconia (YSZ 8mol%) is reported as a function of different heat treatment durations. The as-prepared glass with 10mol% of yttria shows limited amount of crystallization at 800°C. Due to this yttria-based glasses BaY and SrY have been chosen to make diffusion couples with high-temperature electrolyte and interconnect material. These diffusion couples have been heat treated at 850°C, for 100, 200, and 500h. The heat-treated diffusion couples have been characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). Microstructural analysis of diffusion couples shows absence of any undesired oxides and detrimental reaction products at the interface. The glass has shown good bonding characteristics and absence of cracks, pores, or any kind of delamination from YSZ. Apart from this, SrY and BaY glass seals have also shown good adhesion characteristics with Crofer 22 APU, even after 500h at 850°C. The morphology and microstructure of the glass matrix suggest limited amount of devitrification in the glass.