Effect of cathode geometry on the electrochemical performance of flat tubular segmented-in-series(SIS) solid oxide fuel cell

A flat tubular segmented in series (SIS)-SOFC was fabricated with variable cathode thicknesses and the performance characteristics were analyzed. Vacuum slurry dip coating and screen printing technique were employed to coat the NiO-Ce1ScSZ10 anode, Ce1ScSZ10 electrolyte, and La0.6Sr0.4Co0.2Fe0.8 cathode on the extruded 3YSZ ceramic support. A sub module consisting of 5-cell with a total active electrode area of 4 cm2 was interconnected in series using Ag-glass composite. Electrochemical performance analysis was conducted between 600 and 800 °C using 300 CC/min. 3 vol.% humidified hydrogen fuel and 1500 CC/min. air as oxidant. The results obtained from electrochemical impedance spectroscopy and current-voltage polarization curves revealed a 57 μm thick cathode layer as the optimum thickness. An application of LSCo as the cathode current collector on the surface of the cathode enhanced the performance by approximately 30% at 750 °C.