Chemical compatibility between MgO–SiO2–B2O3–La2O3 glass sealant and low, high temperature electrolytes for solid oxide fuel cell applications

The chemical interaction study of MgO–SiO2–B2O3–La2O3 (ML) glass with low and high-temperature electrolytes is reported as a function of different heating durations. The as prepared diffusion couples with high-temperature and low temperature electrolytes have been heat-treated at 850 °C and 800 °C, respectively, for 5, 100 and 750 h. The heat-treated diffusion couples have been characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray dot mapping and electron probe microanalysis (EPMA). Microstructural analysis of diffusion couples completely precludes the presence of any unwanted oxides and reaction products at the interface. The glass has shown good bonding characteristics and absence of delamination particularly with yttria stabilized zirconia (YSZ). Efforts have also been made to understand the interfacial reaction by considering different theoretical parameters associated with ML glass.

► MgO–SiO2–B2O3–La2O3 glass was checked for its chemical compatibility with electrolytes YSZ and TBV.
► New parameters like fg and bulk thermal expansion coefficient have been calculated for the ML glass.
► The prepared diffusion couples were studied as a function of different heating time durations.
► Glass seals were mechanically removed from diffusion couple for XRD analysis.
►  The interface and microstructure were morphologically characterized by using SEM/EPMA.