Abstract:

Highly porous yttria stabilized zirconia (YSZ) supported dense (ZrO2)0.89(Sc2O3)0.1(CeO2)0.01 (10ScSZ-1CeO2) bilayers were fabricated by removing NiO with a reduction-acid leaching method using NiO-YSZ/10ScSZ-1CeO2 half cells that were prepared by dry-pressing. By allowing Ce and Cu nitrate solutions to infiltrate the porous YSZ matrix, single cells of Cu-CeO2-YSZ/10ScSZ-1CeO2/LSCF (LSCF: La0.6Sr0.4Co0.2Fe0.8O3-δ) were fabricated. The cell's structure was characterized by X-ray diffractometry (XRD) and field-emission scanning electron microscopy (FESEM). Results showed that the porous YSZ matrix of the YSZ/10ScSZ-1CeO2 bilayers prepared by the reduction-acid leaching method was of high porosity (more than 64%) and it was highly connected, which was beneficial for the introduction of Ce and Cu nitrate by infiltration. The 10ScSZ-1CeO2 electrolyte filmwith a thickness of 30 μm was dense and pinhole-free. A single cell composed of Cu-CeO2-YSZ/10ScSZ-1CeO2/LSCF showed excellent generation performance with maximum power densities of 0.29 and 0.09 W·cm-2 at 650 ℃, as well as 0.48 and 0.21 W·cm-2 at 700 ℃using moist hydrogen and methane as fuel, respectively. This excellent performance is attributed to the electrolyte's small ohmic resistance, small cathode polarization resistance, and favorable anode microstructure.

Key words: Solid oxide fuel cell, Methane, Cu-CeO2, Anode, Infiltration