Effect of nickel oxide/yttria-stabilized zirconia anode precursor sintering temperature on the properties of solid oxide fuel cells

An NiO/yttria-stabilized zirconia (YSZ) layer sintered at temperatures between 1100 degrees and 1500 degrees C onto dense YSZ electrolyte foils forms the precursor structure for a porous Ni/YSZ cermet anode for solid oxide fuel cells. Conflicting requirements for the electrochemical performance and mechanical strength of such cells are investigated. A minimum polarization resistance of 0.09 Omega.cm(2) at 1000 degrees C in moist hydrogen is obtained for sintering temperatures of 1300 degrees-1400 degrees C. The mechanical strength of the cells decreases with increased sintering temperature because of the formation of channel cracks in the electrode layers, originating in a thermal expansion coefficient mismatch between the layers.