Preparation and electrical properties of La 0.4Sr 0.6Ni 0.2Fe 0.8O 3 using a glycine nitrate process

Abstract

Perovskite structured La 0.4Sr 0.6Ni 0.2Fe 0.8O 3 (LSNF) powder was prepared by a glycine nitrate process (GNP). The electronic conductivity of LSNF was investigated using a four-probe technique. The crystal structure of GNP-derived LSNF was analyzed with X-ray diffraction. The possibility of using LSNF as cathodes for solid oxide fuel cells (SOFCs) was investigated in symmetric cells at temperature between 500 and 850 °C. The interfacial polarization resistance between LSNF cathodes and samaria-doped ceria (SDC) electrolyte was studied by impedance measurement. The effect of firing temperature and SDC addition on the interfacial resistance was systematically studied. Results show that the optimum firing temperature is about 950 °C, whereas the optimum amount of SDC addition is about 45 vol.% in the LSNF–SDC composite; polarization resistances for this LSNF–SDC cathode was as low as 0.16 Ω cm 2 at 700 °C and 0.06 Ω cm 2 at 800 °C, indicating LSNF is a promising cathode for intermediate temperature SOFCs based on doped ceria electrolytes.