Abstract: During manufacture of an SOFC assembly, an inhibitor is included to prevent migration of silver braze during subsequent use of the SOFC assembly. The inhibitor may take any of several forms, either individually or in combination. Inhibitors comprehended by the present invention include, but are not limited to: a) a mechanical barrier that can be printed or dispensed onto one or more SOFC stack elements around the braze areas to prevent mechanically-driven migration; b) an electrically insulating feature in the electrolyte or interlayer over the electrolyte layer in the seal margins to prevent electrical potential-driven migration; and 3) chemical modification of the braze itself as by addition of an alloying metal such as palladium.

Abstract: During manufacture of an SOFC assembly, an inhibitor is included to prevent migration of silver braze during subsequent use of the SOFC assembly. The inhibitor may take any of several forms, either individually or in combination. Inhibitors comprehended by the present invention include, but are not limited to: a) a mechanical barrier that can be printed or dispensed onto one or more SOFC stack elements around the braze areas to prevent mechanically-driven migration; b) an electrically insulating feature in the electrolyte or interlayer over the electrolyte layer in the seal margins to prevent electrical potential-driven migration; and 3) chemical modification of the braze itself as by addition of an alloying metal such as palladium.

Abstract: A glass ceramic composition for sealing adjacent metal cassettes in an SOFC stack. The seal composition comprises an alumina-silicate glass ceramic matrix and a ceramic fiber aggregate dispersed in the matrix. Preferably, the fiber is selected from the group consisting of zirconium oxide fiber, alumina fiber, and combinations thereof. Preferably, the fiber is present at 1-60 weight percent with respect to the weight of glass ceramic, preferably about 30 weight percent. Preferably, the zirconia is stabilized by up to about 10% yttria. Alumina fiber may substitute for a portion of the zirconia fiber. Preferably, a green seal is die cut from a green tape sheet formed by extrusion of a slurry comprising water and a latex binder. The green seal is sintered during the final SOFC stack assembly process to form the final stack seal.