Electrical characterization of co-precipitated LaBaCo2O5+δ and YBaCo2O5+δ oxides

REBaCo2O5+δ layered perovskite oxides (RE = Rare Earth) are promising cathodes for IT-SOFCs. In this work, a simple co-precipitation synthesis in aqueous medium was applied to prepare LaBaCo2O5+δ (LBC) and YBaCo2O5+δ (YBC) cathodes. The chemical and electrochemical properties of both materials were characterized via XRD, SEM, TPO, TG–DTA, 4-probe conductivity measurement, and EIS tests on symmetric cells. The coprecipitation synthesis revealed a promising preparation route: the measured ASR values of both materials were well comparable with the literature ones. A kinetic investigation of the O2 reduction process was performed on LBC (600–800 °C, 5–100% O2, v/v), whose results were analyzed with equivalent circuits. The main steps were identified (oxygen diffusion and charge transfer at high frequency, O2 chemisorption at medium frequency), and their activation energy and reaction order were quantified. Aging tests (500 h time on stream, 500–800 °C) revealed quick deactivation for YBC and good stability for LBC.