Development and Characterization of Glass and Glass Ceramic Sealants for Solid Oxide Electrolyser Cells

The efficiency of glass ceramic sealants plays a crucial role in Solid Oxide Electrolyser Cell performance and durability. In order to develop suitable sealants, operating at about 800 degrees C, several glass formulations from the high silica alkali borosilicate glasses - that will create a glass sealant - and CaO-Al2O3-SiO2 system that will create a glass ceramic sealant - have been prepared and investigated. Thermal and physicochemical properties of the glasses and glass ceramics along with the crystallization behavior were investigated. The glass transition temperatures (Tg) of the prepared glasses were found to be within the range of (600-730 degrees C). Shrinkage, sintering, softening, deformation and crystallization temperatures of the parent glasses have been measured by Hot Stage Microscopy (HSM). Microstructure and chemical composition of the crystalline phases have been investigated using microprobe analysis. Bonding characteristics as well as chemical interactions of the parent glass with yttria-stabilized zirconia (YSZ (R)) electrolyte and high chromium steel-based interconnect (Crofer (R)) have also been studied.