Self-supporting thin yttria-stabilised zirconia electrolytes for solid oxide fuel cells prepared by laser machining

Abstract

A novel procedure to make self-supporting thin yttria-stabilised zirconia (YSZ) membranes by laser machining is shown. We have used a galvanometric controlled laser beam to machine the surface of a conventional sintered YSZ plate and achieved thin areas up to 10 µm thick, but also maintaining thicker support beams to ensure the structural strength of the membrane. The outer areas of the plate are left unaltered to facilitate the sealing of the cell. This kind of thin membrane is ideal for preparing electrolyte-supported Solid Oxide Fuel Cells (SOFC) operating at intermediate temperatures. The membranes have been characterized by optical profilometry, Raman Spectroscopy and Electrochemical Impedance Spectroscopy. The YSZ properties, except those derived from membrane thinning, remain unaltered by processing. Using the laser machined YSZ electrolyte a conventional electrolyte supported YSZ-Ni/YSZ/LSM-YSZ planar single cell with average electrolyte thickness of less than 50 µm has been fabricated and characterized. Performance of the cell is improved as a result of the thinning process.