Influence of Calcination on the Properties of La<sub>0.6</sub>Sr<sub>0.4</sub>Co<sub>0.2</sub>Fe<sub>0.8</sub>O<sub>3-δ-</sub>Samarium Doped Ceria Carbonate

Abstract

The correlation between calcination temperature and properties (physical and electrochemical) of composite cathodes comprising lanthanum strontium cobaltite ferrite (LSCF) with samarium-doped ceria carbonate (SDCC) has been investigated. LSCF-SDC carbonate (LSCF-SDCC) composite cathode powders prepared via ball-milling were calcined at various temperatures in the range of 700850 °C. X-ray diffraction (XRD) results confirmed that the applied calcination temperatures do not affect the chemical compatibility and the LSCF perovskite cubic structure of the composite powders. FTIR spectra verified the presence of carbonates in the composite powders after calcination. The increment of the calcination temperature reduced the surface area of the particle from 10.9 m2/g to 6.5 m2/g. The electrochemical results revealed that the resistance of LSCF-SDC carbonate composite cathodes is dominated by the oxygen surface exchange reaction at the electrode surface. 750 °C was identified as the most appropriate calcination temperature for the LSCF-SDC carbonate powder when the cathode electrode showed the lowest resistance with conductivity value of 0.95 x 10-3 Scm-1. The findings are of potential relevance to utilizing the LSCF-SDC carbonate cathodes for low temperature solid oxide fuel cells (LT-SOFC).