Patent ID: 8420278

Claim:
A solid oxide fuel cell stack comprising: a first cassette having a first sealing surface; a second cassette having a second sealing surface complementary to said first sealing surface, wherein said second cassette is disposed proximate to said first cassette such that said second sealing surface is oriented toward said first sealing surface; and a glass composite seal disposed between said first and second sealing surfaces, thereby joining said first cassette to said second cassette; wherein said glass composite seal comprises an alkaline earth aluminosilicate (AEAS) glass and a viscous glass; wherein said viscous glass is a single continuous portion sandwiched between and in direct contact with said first and second sealing surfaces; wherein said viscous glass includes a perimeter defined by a surface portion of said viscous glass that not in contact with said first and second sealing surfaces; and wherein said AEAS glass surrounds said perimeter of said viscous glass and is in contiguous contact with said perimeter of said viscous glass together with said sealing surfaces such that said AEAS glass retains said viscous glass in a predetermined position between said first and second sealing surfaces.