Validation of BaIn0.3Ti0.7O2.85 as SOFC Electrolyte with Nd2NiO4, LSM and LSCF as Cathodes

Due to its high ionic conductivity level, BaIn0.3Ti0.7O2.85 (BIT07) is a potential electrolyte material for SOFC. In order to validate the use of this material, its chemical, mechanical and electromechanical compatibilities with three classical cathode materials (La0.7Sr0.3MnO3-delta (LSM), La0.58Sr0.4Co0.2Fe0.8O3-delta (LSCF) and Nd2N) have been tested. The chemical compatibility has been demonstrated by XRD experiments, which show that BIT07 does not react with the cathode materials below 1,000 degrees C. The mechanical compatibility has been investigated by combining measurements of the thermal expansion coefficients of the cathode materials from X-ray thermo diffraction and SEM observations Symmetrical cells cathode/electrolyte/cathode have been studied by electrochemical impedance spectroscopy in order to quantify the quality of the cathode/electrolyte interface and to study the long-term stability of the cell. The main conclusion of the study is that LSCF presents the best compromise between an acceptable mechanical compatibility and very good electrical properties with BIT07.