Fabrication and Characterization of Anode-Supported Low-Temperature SOFC Based on Gd-Doped Ceria Electrolyte

摘要

Large-size, 9.5cm×9.5cm, Ni-Gd_(0.1)Ce_(0.9)O_(1.95) (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 bilayer can be fabricated by adding 10 wt.% of pore-former into the composite anode and pre-sintering it at 1,100℃ for 2 h. Composite cathode, La_(0.6)Sr_(0.4)Fe_(0.8)Co_(0.2)O_3, 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℃ and 953 mW cm~(-2) at 650℃ with hydrogen as fuel and air as oxidant.