One-step sintering process of gadolinia-doped ceria interlayer–scandia-stabilized zirconia electrolyte for anode supported microtubular solid oxide fuel cells

A microtubular solid oxide fuel cell (SOFC) consisting of Gd-doped CeO2 (GDC) interlayer–Sc stabilized zirconia (ScSZ) electrolyte has been prepared on an anode supported tube using one step sintering process at 1350 °C. The cell performance under high fuel utilization condition, with H2 flow rate as low as 4.3 mL min−1 per 1 cm2 electrode area is evaluated. The one-step sintering process results in an improvement of open circuit voltage but an increase of ohmic resistance due to possible high resistive layer and voids observed between GDC and ScSZ layers. The performance of the cell shows power densities of 0.35–0.57 W cm−2 with corresponding energy efficiencies of 45–20% (LHV), respectively, at 700 °C. Impedance analyses at different voltages have shown that the overpotential due to gas transport is dominant in the low current density region.

► Shows the effectiveness of one step sintering process of GDC interlayer–ScSZ electrolyte.
► High energy efficiency of 45% was realized at 700 °C.
► Dominant factor of overpotential at lower current density can be gas transport.