Fabrication and characterization of anode-supported low-temperature SOFC based on Gd-Doped Ceria electrolyte

Abstract

Large-size, 9.5 cm × 9.5 cm, Ni-Gd0.1Ce0.9O1.95 (Ni-GDC) anode-supported solid oxide fuel cell (SOFC) has been successfully fabricated with NiO-GDC anode substrate prepared by tape casting method and thin-film GDC electrolyte fabricated by screen-printing method. Influence of the sintering shrinkage behavior of NiO-GDC anode substrate on the densification of thin GDC electrolyte film and on the flatness of the co-sintered electrolyte/anode bi-layer was studied. The increase in the pore-former content in the anode substrate improved the densification of GDC electrolyte film. Pre-sintering temperature of the anode substrate was optimized to obtain a homogeneous electrolyte film, significantly reducing the mismatch between the electrolyte and anode substrate and improving the electrolyte quality. Dense GDC electrolyte film and flat electrolyte/anode bi-layer can be fabricated by adding 10 wt.% of pore-former into the composite anode and pre-sintering it at 1,100 °C for 2 h. Composite cathode, La0.6Sr0.4Fe0.8Co0.2O3, and GDC (LSCF-GDC), was screen-printed on the as-prepared electrolyte surface and sintered to form a complete single cell. The maximum power density of the single cell reached 497 mW cm–2 at 600 °C and 953 mW cm–2 at 650 °C with hydrogen as fuel and air as oxidant.