Corrosion Resistance of SOFC and SOEC Glass-Ceramic Seal Materials in High Temperature Steam/Hydrogen

There exists concern that glass-ceramic seal materials may not tolerate the high temperature gaseous environment in solid oxide fuel cell (SOFC) and solid oxide electrolysis cell (SOEC) applications, potentially leading to the poisoning of electrodes by silica and ultimate loss of hermeticity. A mechanism for the loss of silicon from glass seals has been proposed by other workers. To address this concern, material samples of proprietary glass-ceramics were exposed to steam/hydrogen atmospheres at 800 °C for up to 1000 h. The mass losses of the samples were measured at intervals and their changes in surface chemistry were analyzed using techniques such as X-ray photoelectron spectroscopy and dynamic secondary ion mass spectroscopy. It was shown that the extent of corrosion depends on composition and surface microstructure and that some glass-ceramics are particularly resistant to steam/hydrogen corrosion.