Study of Chemical Compatibility and Interfacial Resistance Between Oxide Cathode Materials and A LaGao₃ –Based Electrolyte for Solid Oxide Fuel Cells

Abstract

The chemical compatibility of (La0.6Sr0.4)MnO3 (LSM), (La0.6Sr0.4)CoO3 (LSC), (La0.6Sr0.4)(Co0.2Fe0.8)O3 (LSCF), and (La1.7Sr0.3)CuO4 (LSU) as cathode materials with the oxygen conductor (La0.9Sr0.l)(Ga0.8Mg0.2)O3-δ (LSGM) was studied. The interfacial resistance between the cathode materials and LSGM was measured using AC impedance spectroscopy. The same studies were done with yttria-stabilized zirconia (YSZ) electrolyte. The results showed that no new compounds formed between LSGM and the cathode materials LSM, LSC, and LSCF up to at least 1200°C; however, a solid solution formed between the materials. With YSZ, only LSM did not form new compounds, and no solid solutions formed. The interfacial resistance was much lower between all the cathode materials and LSGM than YSZ. The lowest interfacial resistances were for LSC/LSGM and LSCF/LSGM, which are suggested for medium temperature solid oxide fuel cells.