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 $Ce0.9Gd0.1O1.95$ (GDC) electrolyte with a NiO–GDC anode on a porous $La0.6Sr0.4Co0.2Fe0.8O3−δ$∕GDC tube (⁠$460μm$ wall thickness and $2.26mm$ diameter). Densification of the ceria membrane (thickness $<20μm$⁠) 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 $2cm$ tube length fed with humidified $30vol%$$H2–Ar$ (3% $H2O$⁠) produced the maximum power densities of $0.09Wcm−2$⁠, $0.08Wcm−2$⁠, and $0.05Wcm−2$⁠, at $600°C$⁠, $550°C$⁠, and $500°C$⁠, respectively.