Glass-diopside composite sealing material for planar solid oxide fuel cells.

Sealants based on glass have been widely used in solid oxide fuel cell (SOFC), and have shown considerable potentials due to their low leakage rate. We report a tape of sealant made by adding different contents of diopside into silicate glass, which has a coefficient of thermal expansion (CTE) matching that of adjacent components. Glass-diopside composite sealing material can block the diffusion of chromium from interconnect has been studied. The structure of the 20 wt% diopside doped silicate glass is stable at high temperatures with leakage rates less than 0.004 sccm∙cm−1, and no crystal except for diopside is found in XRD analysis after heating at 750 °C for 100 h. Excellent interface compatibility between the sealant and SUS430 interconnect was proved by SEM at 750 °C for 100 h. The above results prove the possibility of using glass-diopside composite sealing material for SOFC applications. • A composite sealing material is designed by doping diopside into glass. • The CTE of composite sealing material matches that of the adjacent components. • The composite sealing material doped with 20 wt% shows good sealing properties. • The designed composite sealing material has excellent resistance to Cr diffusion. [ABSTRACT FROM AUTHOR]