Analysis on compatibility between glass-ceramic sealants and the components of solid oxide fuel cells

The SrCO3-Al2O3-SiO2(SAS) glass-ceramic materials have been investigated as SOFC(solid oxide fuel cells) sealants. Sealants with different thermal expansion coefficient alpha values were prepared by adjusting the SrCO3 content in the raw materials. In the study, the sealant material which has the a 12.52 x 10(-6)K(-1) from 25 degrees C to 850 degrees C achieved the best sealing effect. The first reason for this lies in that the a of the sealant matches well with other components of the cells from 25 degrees C to 900 degrees C, including the La0.8Sr0.2MnO3 (LSM) cathode, YSZ electrolyte and the Fe-Cr alloy interconnect. Furthermore, this kind of sealant also maintains a high stability at the operating temperature of the SOFC and its mass loss was only 0.378% after being heat-treated at 800 degrees C for 140 h. According to the test, the cell sealed by this kind of sealant possesses an open voltage of 1.03 V and a power density of 183 mW/cm(2). Thus, this material can work well as a sort of glass-ceramic sealants for SOFCs.