Thermal cycling of Crofer22APU-sealant-anode supported electrolyte joined structures for planar SOFCs up to 3000 h

摘要

Thermal cyclic tests in air were performed for Crofer22APU/glass-ceramic/Anode-Supported-Electrolyte (ASE) joined samples for a total period of 3000 h. Different cooling rates from the SOFC operating temperature of 800 ℃ to room temperature were carried out Large and elongated voids were observed to develop just below the Cr_2O_3/Cr-Mn spinel layer of the Crofer22APU. Diffusion of Al to the areas just below the protective oxide layer led to formation of A1_2O_3 on the surface of the voids. The emergence of CaAl_2Si_2O_8 as a new phase in the glass-ceramic was attributed to the diffusion of Ca away from the interfacial areas thus decreasing the proportion of Ca to Al and Si. The glass-ceramic sealant maintained good adherence with the Crofer22APU and the ASE without presence of any crack even after 3000 h of exposure.