An investigation of the interfacial stability between the anode and electrolyte layer of LSGM-based SOFCs

Abstract

LSGM is known to have very serious interfacial reactivity with other unit cell components even though it is one of the most favorable solid electrolytes for intermediate-temperature SOFCs. Above all, the formation of a La-deficient La-Sr-Ga-O phase at the LSGM/NiO or the LSGM/CeO2 interface is most problematic in LSGM-based SOFCs due to the very resistive nature of its electrical property in fuel cell operating conditions. In this study, we investigated the interfacial reactions in LSGM-based SOFCs under various fabrication conditions, in order to discern a method to either avoid or diminish the undesirable influence of these interfacial reactions. Microstructural evolution due to the chemical reactions between the anode and electrolyte layer were characterized with an Environmental Scanning Electron Microscopy (ESEM-PHILIPS XL-30) and an Energy Dispersive X-ray (EDX-Link XL30) analysis. The spatial distributions of each constituent element at the interfaces were thoroughly investigated with an Electron Probe Micro-Analyzer (EPMA-JEOL. JXA-8600).