Compliant alkali silicate sealing glass for solid oxide fuel cell applications: Thermal cycle stability and chemical compatibility

Compliant alkali silicate sealing glass for solid oxide fuel cell applications: The effect of protective alumina coating on electrical stability in dual environment

“…EDS analysis of these elongated precipitates (listed in Table 3) showed the major components were Al, K, and Si with traces of other elements all less than w0.5 at%. The atomic ratio of K:Al:Si was 1:0.86:3.9, close to KAlSi 3 O 8 , consistent with observations in a previous thermal cycling study [27]. The uniform distribution of elongated KAlSi 3 O 8 precipitates was consistent with classical nucleation and crystallization, commonly observed in glass.…”

“…A recent review on glass and glasseceramic-to-metal seals addressed the development in the preparation, characterization, and applications not only to SOFC but also to biomedical use [26]. Recently, a different approach based on compliant glass was proposed for SOFC application [5,21,27]. The compliant glass, contrary to conventional glasseceramics, will remain vitreous without substantial crystallization and retain compliant behavior after sealing.…”

“…However, the ability to maintain a vitreous state without crystallization at SOFC operation conditions over the long periods of time remains unknown. In earlier work, an alkali-containing (K þ Na 17 mol %) compliant silicate sealing glass (SCN-1) was studied in terms of thermal cycling and isothermal aging at elevated temperature when sealed between a YSZ electrolyte and an aluminized AISI441 metal substrate [27]. Results showed minimum reaction at the YSZ and alumina interfaces; however, no DC bias was applied in these studies.…”

Tuning the thermal properties of borosilicate glass ceramic seals for solid oxide fuel cells

“…[24][25][26][27][28] The desired viscosity characteristics are often obtained by the addition of some other oxides, e.g., Na 2 O and K 2 O, 24,25 which impose additional uncertainties on the long-term stability of sealants in the stacks.…”

Viscous Glass Sealants for SOFC Applications

“…Thermal cycling leak testing was used to demonstrate crack healing on reheating the button cell to 900°C or higher. Recent work on viscous sealing from Pacific Northwest National Laboratory is focused on alkali-containing glasses for intermediate operating temperatures [4][5][6][7]. The selected sealant is a commercially available mixed alkali alkaline earth silicate glass.…”