Development and characterization of cathode-supported SOFCs by single-step cofiring fabrication for intermediate temperature operation

In this study, a single-step cofiring through the extrusion molding and wet-ceramic coating technique was developed to fabricate a cathode-supported microtubular cell. The cell is consisting of a Ce _0.9 Gd _0.1 O _1.95 (GDC) electrolyte with a NiO-GDC anode on a porous La _0.6 Sr _0.4 Co _0.2 Fe _0.8 O _3-δ/GDC tube (460 μm wall thickness and 2.26 mm diameter). Densification of the ceria membrane (thickness <20 μm) was successful by cosintering the laminated thin electrolyte and the anode with the cathode at 1200°C. Compared with that fabricated by the conventional two-step cofiring process, the cell showed an improved performance due to the increased anode sintering temperature, which leads to an improved anode /electrolyte interfacial property. The cell having 2 cm tube length fed with humidified 30 vol % H ₂-Ar (3% H ₂O) produced the maximum power densities of 0.09 W cm ², 0.08 W cm ^-2, and 0.05 W cm ^-2, at 600°C, 550°C, and 500° C, respectively.