Self-repairable glass seals for solid oxide fuel cells

Seals are required for a functioning solid oxide fuel cell (SOFC). These seals must function at high temperatures of 600–900 °C and in oxidizing and reducing environments of the fuels and air. Among the different type of seals, the metal–ceramic seals require significant attention, research, and development because the brittle nature of ceramics and glasses leads to fracture and loss of seal integrity and functionality. A novel concept of self-healing/self-repairable glass seals is proposed, developed, and used for making metal–glass–ceramic seals for application in SOFC for enhancing reliability and life. Glasses and glass–ceramics displaying self-healing behavior are investigated and used to fabricate seals. The performance of these seals under long-term exposure at higher temperatures coupled with thermal cycling is characterized. Self-repairability of these glass seals is also demonstrated by leak tests along with the long-term performance. An approach for studying the kinetics of crack healing in glasses and glass–ceramics responsible for self-repair is briefly described.