Evaluation of Ni-YSZ Performance in Anode-Supported Microtubular Solid Oxide Fuel Cells

Ni-yttria-stabilized zirconia (YSZ) anodes, deposited using electrophoretic methods on the inner YSZ surface of microtubular solid oxide fuel cells (mu SOFCs), were evaluated for their performance in humidified H-2 at 800 degrees C. Three-electrode methods, in which the anode layer was the working electrode, could not be reliably employed for this purpose as the geometric area of the inner anode layer is always larger than that of the outer counter electrode. Therefore, the electrochemical performance of the anode layer was determined by first carrying out two-electrode impedance measurements of the full cell (with Ni-YSZ painted on the outer microtube surface), measuring the individual impedance of a smaller area outer Ni-YSZ layer in a standard three-electrode setup, and then subtracting these two values. This revealed that the electrophoretically deposited Ni-YSZ inner layer exhibits excellent electrochemical performance in mu SOFCs, similar to that of other anode support layers.