Fabrication and performance of gadolinia-doped ceria-based intermediate-temperature solid oxide fuel cells

Anode-supported solid oxide fuel cells (SOFC) based on gadolinia-doped ceria (GDC) are developed in this study. A carbonate co-precipitation method is used to synthesize the nano-sized GDC powders. A dense GDC electrolyte thin film supported by a Ni-GDC porous anode is fabricated by dry-pressing and spin-coating processes, respectively. In comparison with dry pressing, it is easy to prepare a thinner electrolyte film by the novel spin-coating method. Cell performance is examined using humidified (3% H2O) hydrogen as fuel and air as oxidant in the temperature range of 500-700 degrees C. Cell performance is strongly dependent on the electrolyte thickness. With a porous Ni-GDC anode, a dense 19-mu m GDC electrolyte film and a porous La0.6Sr0.4Co0.2Fe0.8O3-GDC cathode, the cell exhibits maximum power densities of 130, 253, 386 and 492 mW cm(-2) at 500, 550, 600 and 650 degrees C, respectively. It is also found that at the low operating temperature about 500 degrees C, the cell resistance is significantly dominated by the electrode polarization resistance. (C) 2008 Elsevier B.V. All rights reserved.