Effects of pressurization on cell performance of a microtubular SOFC with Sc-doped zirconia electrolyte

In this study, we fabricated an anode-supported microtubular solid oxide fuel cell (SOFC) with the cell configuration La0.6 Sr0.4 Co0.2 Fe0.8 O3 (LSCF)- Ce0.8 Gd0.2 O1.9 (CGO) cathode/CGO buffer layer/ (ZrO2) 0.89 (Sc2 O3) 0.1 (CeO2) 0.01 (ScSZ) electrolyte/Ni-ScSZ anode. A power generation test of the SOFC was carried out at 0.1-0.7 MPa at 650°C. By using a wet H2 - N2 gas mixture and air, the maximum power density of the microtubular cell was found to be 0.68 W cm-2 (at 2.6 A cm-2, Uf =78%) at atmospheric pressure (0.1 MPa). With increasing the operating pressure, the performance of the cell was improved, and the power density reached 1.48 W cm-2 (at 2.8 A cm-2, Uf =86%). It was confirmed by the current interruption method that both polarization and ohmic resistances decrease under a pressurized condition.