Effect of pre-oxidation and environmental aging on the seal strength of a novel high-temperature solid oxide fuel cell (SOFC) sealing glass with metallic interconnect

Recent developments in the preparation, characterization and applications of glass- and glass–ceramic-to-metal seals and coatings

“…7 [67]. Reactions do, however, become extremely critical during fuel cell operation, and cell ageing is therefore an extremely important aspect [83,[99][100][101][102][103][104][105][106][107][108][109][110][111][112][113][114]. Alkali-containing glass-ceramics are generally to be avoided due to the likelihood of pronounced glassceramic-metal reactions during cell operation.…”

Effect of aluminizing of Cr-containing ferritic alloys on the seal strength of a novel high-temperature solid oxide fuel cell sealing glass

“…Crofer22APU is a special ferritic stainless steel developed for SOFC applications which contains about 22 wt.% of Cr to improve the oxidation resistance while maintaining good oxide scale electrical conductivity. It also contains small amounts of impurities or additives of Mn, Al, Ti, Si, and La (<0.5-0.8 wt.%) [21,26]. The as-received Crofer22APU sheet had a thickness of 0.5 or 1.0 mm and was cut into 12.5 mm × 12.5 mm squares for coating and strength testing.…”

“…No strength degradation was observed when sealed coupons were aged in a reducing environment, due to fact that the chromate phase is not stable in reducing atmospheres and therefore did not form. [21]. A possible solution to the air-side chromate formation was proposed which involved aluminizing the metallic interconnect to form a protective layer of alumina.…”

Effects of La2O3, Nd2O3, NiO and CoO additions on the characteristics of SiO2–Al2O3–Y2O3–ZnO glass seals for intermediate temperature solid oxide fuel cells

“…For example, a sealing glass or glassceramic has to be thermally stable, equipped with a good adherence to the components and a coefficient of thermal expansion (a) between 8.5 and 12 Â 10 À6 K À1 , must be electrically insulating (r > 10 4 U-cm), chemically compatible with the mating materials, and mechanically strong in wet, oxidizing and reducing atmospheres [6]. Numerous glass and glass-ceramic systems, including: alkali oxide, alkaline-earth oxide and rare-earth oxide containing silicates (e.g., (MgO,ZnO)eBaOeSiO 2 ) [7,8], borosilicates (e.g., MgOeSiO 2 eB 2 O 3 and (BaO,SrO,CaO)eY 2 O 3 eB 2 O 3 eSiO 2 ) [9e11], aluminosilicates (e.g., (BaO,CaO)eAl 2 O 3 eSiO 2 ) [6,12] or alumomoborosilicates (e.g., AO-Al 2 O 3 eSiO 2 eB 2 O 3 (A ¼ Ba, Ca, Sr and Mg)) and ((BaO,SrO)eLa 2 O 3 eAl 2 O 3 eSiO 2 eB 2 O 3 ) [13e21], have been reported as promising sealing materials for SOFC applications. However, downsides associated with the glass constituents were usually encountered during the applications and reduced the seal life.…”