Effect of Firing Temperature on the Kinetics of Oxygen Reduction in La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) Cathodes for Solid Oxide Fuel Cells

Abstract

In the present work, symmetric cells consisting of La0.6Sr0.4Co0.2Fe0.8O3-delta (LSCF) cathodes and a Ce0.9Gd0.1O2-delta (CGO) electrolyte were fabricated. Both materials were spray-pyrolyzed by CerPoTech AS (Trondheim, Norway), and were received without any further post-treatments. A procedure for obtaining CGO pellets with relative densities in excess of 94% was developed. Furthermore, air brushing was used to deposit LSCF cathodes on the electrolyte pellet. The effect of firing temperature on the kinetics of the oxygen reduction reaction was evaluated by electrochemical impedance spectroscopy (EIS) of symmetric cells fired at 950 C, 1000 C, 1050 C and 1100 C. Furthermore, the obtained data were correlated with features of the microstructure as documented by SEM.