Glass-Ceramic Seal Stability Study for Solid Oxide Electrolyzer/Fuel Cells

摘要

Stability of glass-ceramic based sealant material is a critical issue for solid oxide electrolyzer/fuel cells operating at 600-1000 deg C. SrO-La_2O_3-Al_2O_3-B_2O_3-SiO_2 based sealant materials with varying composition have been synthesized by quenching in graphite mold and controlled furnace cooling at 10 deg C/min. To investigate the effect of composition and preparation method on the stability of the glass-ceramics, the synthesized materials are characterized by differential scanning calorimetry (DSC) and dilatometry to evaluate their thermophysical properties and microstructural evolution, i.e. glass transition temperature, dilatometric softening temperature, thermal expansion coefficient, and crystallization temperature. Increasing Al_2O_3 content results in higher glass transition temperature. Microstructural studies have been performed by X-ray diffraction and scanning electron microscopy to understand the phase changes during thermal cycling.