Improved sintering of a rigid seal for high-temperature SOEC/SOFC through the addition of a compliant glass

Glass seals play a critical role in the efficiency, durability, and long-term stability of Solid Oxide Cells. Among the various sealing technologies developed for SOC applications, rigid glass seals are considered promising due to their high thermal and chemical stability. However, their relatively high sealing temperature remains a significant limitation, as it can induce degradation of other cell components. To address this challenge, a novel approach was investigated, involving the combination of a rigid glass with a low-temperature compliant glass. The results demonstrate that its incorporation reduces the sealing and self-healing temperatures while enhancing crack-healing ability. However, a sufficient compliant glass content is required to maintain a dense and adherent glass / metal interface. NMR analyses revealed significant interdiffusion phenomena between the two glass phases during thermal aging. Overall, mixed rigid / compliant glass seals emerge as promising candidates for enhancing the sealing performance and long-term stability of SOECs.