Improved Sr0.6La0.4Co0.8Fe0.2O3-δ/Ce0.8Y0.2O2-δ interface for IT-SOFC applications

Abstract

One of the remaining challenges for the solid oxide fuel cell (SOFC) technology is decreasing its operation temperature to the 500-800 °C range in a cost-effective way without diminishing the cell performance. In this work, we studied a symmetrical cell composed of Sr0.6La0.4Co0.8Fe0.2O3-δ (LSCFO) cathodes deposited on a Ce0.8Y0.2O2-δ (CYO) substrate by the simple, cost-effective and scalable spin coating technique. The nanostructured cathode is composed of agglomerated ∼100-200 nm particles with ∼50 nm crystallite size. Electrochemical impedance spectroscopy (EIS) analysis indicates that electrolyte grain boundary conductivity strongly depends on the cathode nature. The detailed high resolution transmission electron microscopy (HR-TEM) characterization of the LSCFO/CYO interface reveals that the LSCFO cathode is well adhered to the CYO electrolyte. The improved nano/microstructure of the cathodes and the cathode/electrolyte interface yields to cathode area specific resistance (ASR) values as low as 0.4 Ωcm2 at 550 °C, being these values even lower than those previously reported in literature for cathodes in optimized LSCFO/CYO/YSZ/CYO/LSCFO cells.