Optimization of Sm0.5Sr0.5CoO3−δ–Sm0.2Ce0.8O2−δ composite cathodes fabricated by electrostatic slurry spray deposition

Strontium doped samarium cobaltite (Sm0.5Sr0.5CoO3−δ, SSC)–samarium doped ceria (Sm0.2Ce0.8O2−δ, SDC) composite cathodes were fabricated using the electrostatic slurry spray deposition method for intermediate temperature solid oxide fuel cells (IT-SOFCs). To optimize the performance of the full cell containing the fabricated composite cathode, the effects of sintering temperature, composite ratio between SSC and SDC components, and film thickness of the composite cathode have been investigated through SEM, EDS and EIS analysis. As per the results, the best electrochemical performance was obtained from the SSC–SDC composite cathode sintered at 1000 °C in the weight ratio of 60:40 and with 20 μm in thickness. The cathode sintered at 1000 °C showed better performance than the cell sintered at 900 °C due to the well-developed connectivity between the SSC and the SDC particles. Also, the 60SSC–40SDC composite cathode showed an excellent percolating property and the lowest polarization resistance was obtained from the composite cathode with 20 μm in thickness due to its well developed microstructure in terms of gas diffusion and TPB area.