Solid oxide fuel cells sealant

J.W. Fergus, Sealants for solid oxide fuel cells, Journal of Power Sources, 147, pp. 46-57 (2005). 

N. Lahl et al. Aluminosilicate Glass Ceramics as Sealant in SOFC Stacks, Solid Oxide Fuel Cells Vol. VI, Electrochemical Society Proceedings Vol. 99-19, pp. 1057-1066. 

Abstract Single-chamber solid oxide fuel cells (SC-SOFCs) immerse the entire cell in a mixture of fuel and oxidizer gases within a single chamber, which eliminates the need for high temperature sealant, simplifies construction, and increases reliability over traditional double-chamber cells. However, there are challenges, such as low fuel utilization and electrode catalytic selectivity, that need to be overcome. This brief review paper looks at recent improvements in materials, processing, and operation of SC-SOFCs, which are rapidly approaching the performances of the double-chamber fuel cells and may become attractive for specific fuel cell applications. 

Development of planar solid oxide fuel cells (SOFCs) and other electrochemical devices, such as oxygen generators and sensors, makes it necessary to elaborate sealant materials for hermetization in high-temperature zone. The sealants should satisfy numerous requirements, including chemical stability, good adhesion and thermal expansion. 

K. Ley, M. Krumpelt, R. Kumar, et ah. Glass-ceramic sealants for solid oxide fuel cells Part I. Physical properties. Journal of Materials Research, 11 (1996) 1489-1493. 

S.B. Sohn, S.Y Choi, G.H. Kim, et ah. Suitable glass-ceramic sealant for planar solid-oxide fuel cells. Journal of the American Ceramic Society, 87 (2004) 254-260. 

I.D. Bloom and K.L. Ley. Compliant sealants for solid oxide fuel cells and other ceramics, US Patent No. 5453331, Sept. 26, 1995. 

Kumar, V., Arora, A., Pandey, O.P., and Singh, K. (2008) Studies on thermal and structural properties of glasses as sealants for solid oxide fuel cells. Int.J. Hydrogen Energy, 33, 434-438. 

Meinhardt, K.D., Kim, D.S., Chou, Y.S., and Weil, K.S. (2008) Synthesis and properties of a barium aluminosilicate solid oxide fuel cell glass-ceramic sealant. J. Power Sources, 182, 188-196. 

Sun, T., Xiao, H., Guo, W., and Hong, X. (2010) Effect of AI2O3 content on BaO — AI2O3 — B2O3 — Si02 glass sealant for solid oxide fuel cell. Ceram. Int, 36, 821-826. 

Ghosh, S., Das Sharma, A., Kundu, P., and Basu, R.N. (2008) Glass-based sealants for application in planar solid oxide fuel cell stack. Trans. Indian Ceram. Soc., 67, 5748-5754. 

Pascual, M.J., Guillet, A., and Duran, A. (2007) Optimization of glass-ceramic sealant compositions in the system MgO—BaO—Si02 for solid oxide fuel cells (SOFC)./. Power Sources, 169, 40-46. 

D Herin Bytner, F.D., Leone, P., and Ferraris, M. (2010) New glass and glass-ceramic sealants for planar solid oxide fuel cells. J. Eur. Ceram. Soc., 30, 933-940. 

Wenning N. L., Sun, X., Koeppel, B., and Stephens, E. (2011) Creep behavior of glass/ceramic sealant and its effect on long-term performance of solid oxide fuel cells. Int. J. Appl. Ceram. Technol, 8 (1), 49-59. 

The solid oxide fuel cell is highly influenced by the temperature variation during operation, constantly suffering from thermal stress, which requires excellent compatibility between the thermal expansion coefficients of the cell components. The cylindrical shape of tubular SOFC contributes significantly to minimize the difference in the coefficients of thermal expansion, thus avoiding the formation of cracks and delamination. This model also makes unnecessary the use of sealant gases. On the other hand, the efficiency is impaired, since the path made by the electric current is increased, causing ohmic losses (Minh, 1993). 

H.-T. Chang, C.-K. Lin, C.-K. Liu, High-temperature mechanical properties of a glass sealant for solid oxide fuel cell. J. Power Sources 189(2), 1093-1099 (2009)... 

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