LSC cathode prepared by polymeric complexation method for proton-conducting SOFC application

Abstract

Single-phase, submicron La0.6Sr0.4CoO3−δ (LSC) powder was prepared via a polymeric complexation method at various heating/cooling rates. The optimum powder slurry was used to fabricate LSC/BCZY64/LSC half-cells using BaCe0.54Zr0.36Y0.1O2.95 (BCZY64) as the electrolyte material. The produced powder was characterized by thermal gravimetric analyzer (TGA), X-ray diffractometer (XRD) and scanning electron microscope (SEM) and the half-cell, by electrochemical impedance spectroscopy. TGA results showed that the thermal decomposition temperature (T td) increased as the heating rate increased. The minimum and maximum T td was observed at 600 °C (2 °C min−1) and 750 °C (15 °C min−1), respectively. The XRD results confirmed that a single perovskite phase of LSC formed at heating/cooling rates of 2, 5 and 10 °C min−1 at calcination temperatures of 800, 900 and 1000 °C, respectively. A single perovskite phase of LSC was not observed at a heating/cooling rate of 15 °C min−1. The smallest particle size (130–260 nm) was obtained at 800 °C with a heating/cooling rate of 5 °C min−1, as shown in the SEM micrographs. The area specific resistance of the half-cell was 2.96, 0.97, 0.48 and 0.19 Ω cm2 at 500, 600, 700 and 800 °C, respectively. This result indicates that the prepared LSC cathode has the potential to be used with the BCZY64 electrolyte for an intermediate temperature proton-conducting SOFC.