Long-term ageing and materials degradation of hybrid mica compressive seals for solid oxide fuel cells
Hybrid phlogopite mica seals with silver interlayers were evaluated in long term isothermal ageing tests in a dual environment consisting of dilute hydrogen vs. air at 800 degrees C. High-temperature leak tests with helium showed very stable leakage of 0.01-0.02 sccm/cm for 28366 hrs under a low applied compressive stress of 82 kPa (12 psi). Post-mortem SEM and EDS analyses of the mica showed minimum degradation in terms of changes in microstructure and chemical composition, although there appeared to be some Ag migration and segregation at interstices between mica flakes. Fluorine was also found to be released from mica. Overall, the low, constant leakage through the hybrid mica/Ag seals clearly demonstrated a very promising candidate for SOFC sealing.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 963164
- Report Number(s):
- PNNL-SA-64433; AA2530000
- Journal Information:
- Journal of Power Sources, 191(2):384-389, Journal Name: Journal of Power Sources, 191(2):384-389
- Country of Publication:
- United States
- Language:
- English
Similar Records
Material Degradation During Isothermal Ageing and Thermal Cycling of Hybrid Mica Seals under Solid Oxide Fuel Cell Exposure Conditions
Novel Compressive Mica Seals with Metallic Interlayers for Solid Oxide Fuel Cell Applications