The Effect of Particle Size on the Properties of (La,Sr)(Co,Fe)O3-δ Ferrite- Based Cathodes for SOFCs
La0.6Sr0.4Co0.2Fe0.8O3-δ (L60SCF) and La0.56Sr0.4Co0.2Fe0.8O3-δ (L56SCF) cathodes for IT-SOFC application were prepared by solid state reaction. The mixture was calcined at 950°C for 3 h. The perovskite materials were re-ground, sieved (using 140 and 325 mesh screens to get 2 particle size powders), then pressed into pellet shape at a pressure of 1 ton/cm2 and sintered at 1100-1200 °C for 2 or 4 h. The preliminarily study of phase, particle size distribution, microstructure, density and thermal expansion coefficient were characterized. It was found that the smaller the particles, the less the energy and the lower sintering temperature required for sintering the samples. L56SCF with particle size of 0.37 μm achieved the lowest sintering temperature at 1100 °C for 2 h in this study. The sample showed single phase perovskite product with porous structure. The TEC of the sample was 14.55×10-6(°C)-1.