Performance of Anode Supported Bilayer YSZ/CYO electrolyte SOFC

摘要

The internal resistance of planar SOFC can be lowered through reduction of the electrolyte thickness below 20μm using supporting electrode structures. In the present study anode substrates were produced by tape casting and sintering. Anode supported electrolyte (ASE) cells were prepared by reactive magnetron sputtering of 8mol % Yttria stabilised Zirconia (8YSZ) and Ceria 10mol % Y2O3 solid solution (CYO) electrolyte films from metal alloy target onto micro porous NiO/YSZ substrates of size 0120 mm. First a 5μm thick dense layer of sub stoichiometric YSZ was deposited followed on top by a 1μm coating of CYO. A LaSrCoFe-perovskite slurry was screen printed onto the bilayer electrolyte, dried and used as a cathode at the operating temperature of the cell. The cells were interconnected using ferritic stainless plates with machined current collector structures or corrugated stainless steel sheets. The performance of the cell was characterised in single cell stacks operated on H2 as fuel. Gas diffusion through the support was identified as limiting factor at a fuel utilisation Uf > 60%. The status of the anode supported cell was verified in 5 cell stacks using partially pre-reformed CH4 or natural gas from the grid.