Fabrication and sealing performance of rare-earth containing glass–ceramic seals for intermediate temperature solid oxide fuel cell applications

The opportunity of using two rare-earth metal oxides in an aluminosilicate glass for seal applications was investigated in this work. Substitution of La2O3 with Y2O3 in the system changed thermal and physical properties such as transition temperature, flowing behavior, and thermal expansion. The strongly bound structural unit in the network affected glass healing capability with a slower healing response. Higher activation energy (≥20%) was required for Y2O3 containing glass, consistent with in-situ XRD results which revealed its amorphous nature is maintained ~75°C above the other glass. Despite containing strontium in the composition, well bonded interface was obtained in contact with 8YSZ and SS430 ferritic stainless steel. The hermeticity of the glass seals was maintained after 100h isothermal aging at 800°C. Also the OCV showed insignificant fluctuations with stable average values after 24 thermal cycles.