Three-Layered Membranes for Planar Solid Oxide Fuel Cells of the Electrolyte-Supported Design: Characteristics and Applications

Three-layered ceramic membranes based on stabilized zirconia for planar solid-oxide fuel cell (SOFC) are prepared by the tape casting method. The outer layers containing 94 mol % ZrO 2 –6 mol % Sc 2 O 3 provide the enhanced mechanical stability; the inner layer has the composition of 89 mol % ZrO 2 –10 mol % Sc 2 O 3 –1 mol % Y 2 O 3 which has the highest anionic conductivity in the series of solid solutions ZrO 2 –Y 2 O 3 –Sc 2 O 3 . Studying the mechanical characteristics shows that the ultimate strength (bending strength) of these membranes much exceeds the value typical of single-layered samples. The anionic conductivity of three-layered ceramics is studied by the impedance spectroscopy in the frequency range from 1Hz to 1 MHz. Membrane-electrode assemblies for SOFCs are fabricated and their electrochemical properties are studied under the conditions of fuel cell operation.