Interactions and Compatibilities of LSGM Electrolyte and LSCM Anode

Abstract

Interactions between La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 2.8 (LSGM) electrolyte and La 0.75 Sr 0.25 Cr 0.5 Mn 0.5 O 3 (LSCM) anode in the cell fabricating temperature range (1100-1500°C) were studied using XRD, SEM and EDS techniques. Powder mixtures and bi-layer samples were fired for 2-72 h at 1400-1500°C. Although there were 15-20% differences in firing shrinkage during fabrication, the thermal expansion coefficients of the LSCM anode closely matched (less than Ix10/°C) with the LSGM electrolyte in the fuel cell operating temperature range. There were no interactions detected from XRD data during fabrication under 1500°C and dwell for 2 h. However, severe reactions were found in samples with dwell time 6 h and over at 1500°C to form low conductive phases. EDS analysis indicated that the reaction/diflbsion zones were between 50-150 pm. The overall results suggested that LSCM is a thennonacchanically and chemically compatible anode material with LSGM electrolyte at the fuel cell operating temperatures and fuel cell fabrication conditions (under 1500°C and dwell for 2 h and shorter).