Suitable Glass‐Ceramic Sealant for Planar Solid‐Oxide Fuel Cells

Abstract

Various glass-ceramics were prepared based on the BaO-Al 2 O 3 -B 2 O 3 -SiO 2 system with the addition of La 2 O 3 , ZrO 2 , or NiO in an attempt to develop a suitable sealant for planar solid-oxide fuel cells operating at 800°C. To estimate the applicability of these glasses as suitable sealants, their thermal and chemical stabilities as well as the crystallization behavior and bonding characteristics of their parent glasses were investigated. The thermal properties and crystallization behavior of the parent glasses were dependent on the type of additive used, and the bonding characteristics were strongly influenced by the B 2 O 3 /SiO 2 value in the glass composition. Observation of microstructural change and chemical reaction at the glassceramic/electrolyte interface confirmed that the prepared glass-ceramics possessed long-term stability during heat treatment at the operation temperature for up to 1000 h. Journal of the American Ceramic No. 2 Fig. 6. Changes in CTE values of the various glass-ceramics with long-term heat treatment at 800°C (CTE values were measured from RT to 800°C in air with a heating rate of 5°C/min).

Effect of A2O3 (A=La, Y, Cr, Al) on thermal and crystallization kinetics of borosilicate glass sealants for solid oxide fuel cells

“…Many studies have been performed on glass and glass ceramics to achieve above mentioned properties which can make them suitable as a sealant material for SOFC [11,12]. However, each category of glasses has its own drawbacks such as mismatching of thermal expansion due to formation of various crystalline phases during the operation of SOFC.…”

Crystallization kinetics of a solid oxide fuel cell seal glass by differential thermal analysis

“…This is followed by the formation of hexacelsian BaAl 2 Si 2 O 8 . The BaSiO 3 and hexacelsian were the primary crystalline phases whereas monoclinic celsian (BaAl 2 Si 2 O 8 ) and (Ba x Ca y )SiO 4 were also detected as minor phases. Needle-shaped BaSiO 3 crystals are formed first followed by the formation of other phases at longer times of heat treatments.…”

Microstructure and property evaluation of barium aluminosilicate glass–ceramic sealant for anode-supported solid oxide fuel cell

“…Till date, many studies have been carried out over the application of glasses or glass-ceramics as suitable sealants for high temperature electrochemical devices e.g., SOFCs. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] All three of the primary glass forming oxides viz., B 2 O 3 , P 2 O 5 and SiO 2 have been investigated individually along with other constituents as potential SOFC seals. However, best results have been reported only for compositions based on silica.…”