Sealing Technology for Solid Oxide Fuel Cells (SOFC)

A variety of seals such as metal–metal, metal–ceramic, and ceramic–ceramic are required for a functioning solid oxide fuel cells (SOFC). These seals must function at high temperatures between 600 and 900°C and in oxidizing and reducing environments of the fuels and air. Among the different type of seals, the metal–ceramic and ceramic–ceramic seals require significant attention, research, and development because the brittle nature of ceramics and glasses can lead to fracture and loss of seal integrity and functionality. This paper addresses the needs and possible approaches for high-temperature ceramic–metal seals for SOFC and seals fabricated using some of these approaches. A new concept of self-healing glass seals is proposed, developed, and used for making metal—glass–ceramic seals for potential application in SOFC in order to enhance the reliability and life of a cell. In this study, glasses 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 by leak tests. The self-healing ability of these glass seals is also demonstrated by leak tests along with the long-term performance.