Glass Ceramic fuel seal

T. Yamamoto et al., Application of Mica Glass-Ceramics as Gas-Sealing Materials for SOFC, in Proceedings of the Fourth International Symposium on Solid Oxide Fuel Cells (SOFC-IV), Vol. 95-1, pp. 245-253, The Electrochemical Society (1995). 

The E-design stack, shown in Fig. lA, consists of a relatively thick metallic interconnect with machined gas channels on both sides and a metallic picture frame for the cell, brazed to the interconnect by a metal solder. Sealing is obtained by glass ceramic sealants applied to the planar cell and frame surfaces using an automated dispenser. A fine Ni-mesh is spot-welded to the fuel side of the interconnect in order to improve the electrical contact between interconnect and anode substrate. On the air side usually a lanthanum cobaltite (LC) contact layer is sprayed onto the ribs of the interconnect. 

The central element of the solid oxide fuel cell stack is the SOFC cell which consists of the fuel electrode (anode), the oxygen electrode (cathode), and the ionconducting electrolyte. To reach the desired electrical voltage, single cells are stacked (cf. Fig. 21.11). They are separated by interconnects (plates) and sealed by glass ceramics. 

J. Milhans, S. Ahzi, H. Gannestani, M. Khaleel, X. Sun, B. Koeppel, Modeling of the effective elastic and thennal piopeities of glass-ceramic solid oxide fuel cell seal materials. Mater. Des. 30(5), 1667-1673 (2009)... 

E. Stephens, J. Vetrano, B. Koeppel, Y. Chou, X. Sun, M. Khaleel, Experimental characterization of glass-ceramic seal properties and their constitutive implementation in solid oxide fuel cell stack models. J. Power Sources 193(2), 625-631 (2009)... 

J. C. Leea, H. C. Kwona, Y. P. Kwona, J. Leeb, S. Park, Porous ceramic fiber glass matrixnext term composites for solid oxide fuel cell seals. Colloids and Surfaces A Physicochemical and Engineering Aspects, 300 (2007), pp. 150. 

Solid oxide fuel cells (SOFCs) involve structures composed of multiple ceramic layers, or interleaved layers of ceramic membranes and metal interconnects. To eliminate premature mixing of fuel and air gases or leaking of these gases from interior regions of the structure, the interfaces of adjacent layers are sealed with a glass or ceramic seal. These seals must withstand the high-temperature environment of the SOFC over its lifetime. Therefore these materials must be thermally matched with the adjacent layers to minimize transient stress risers and eliminate the potential for consequent seal failure. 

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