Compliant sealants for solid oxide fuel cells and other ceramics

A glass or glass-ceramic sealant for a SOFC having a coefficient of thermal expansion in the range of from about 8 to about 13x10-6/ DEG C. and a viscosity of at least 103 Pa-s at cell operating temperature. The sealant has a composition of SrO present in the range of from about 5 to about 60 mole percent, La2O3 present in the range of from 0 to about 45 mole percent, Al2O3 present in the range from 0 to about 15 mole percent, B2O3 present in the range of from about 15 mole percent to about 80 mole percent, and SiO2 present in the range of from 0 to about 40 mole percent, wherein the material is a viscous fluid at cell operating temperatures of from about 600 DEG C. to about 1000 DEG C. The sealant may also be compounds of CaO present in the range of from 0 to about 35 mole percent, Al2O3 present in the range from 0 to about 15 mole percent, B2O3 present in the range of from about 35 mole percent to about 85 mole percent, and SiO2 present in the range of from 0 to about 30 mole percent.