The stability of sealing glasses is one of the critical issues concerning the long-term operation of SOFC. Different reasons are responsible for failures of the glass sealings resulting from thermal cycling, stack deformation or chemical degradation due to interactions with fuel gas, interconnectors or protective coatings. Different reactions with an interconnector material (Crofer 22) under oxidizing and reducing conditions lead to crystalline product layers, which affect the bonding strength and microstructure of the sealing material at the interfaces. Effects of externally applied electric voltage on the sealing glass provide insights into mechanisms of reactions at anodically and cathodically polarized interfaces of the interconnector material. Tests of model sealings under electrical voltage in combination with a dual atmosphere reveal additional information about the stability of sealing glasses.
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