Characterization of laser-processed thin ceramic membranes for electrolyte-supported solid oxide fuel cells

By laser machining we have prepared thin and self-supported yttria stabilized zirconia (YSZ) electrolytes that can be used in electrolyte-supported solid oxide fuel cells for reducing the operation temperature. The membranes, which are supported by thicker areas of the same material, have an active area of similar to 20 mu m in thickness and up to 8 mm in diameter. Buckling limits the maximum size of the thin areas to below 1 mm, the overall effective active area being formed by multiple thin areas bounded by ribs. Electron Back scattering Diffraction experiments determined that there are not significant strains inside the membranes and that the heat-affected zone is confined to a shallow layer of similar to 1-2 mu m. The bending strength of the membranes decreases by similar to 26% as a result of the surface microcracking produced by the laser machining. The membranes have a roughness of similar to 2.5 mu m and are coated by a layer of nanoparticles produced by the laser ablation. This coating and small roughness is not detrimental for the cathodic polarization of the cells. Conversely, the cathode polarization resistance decreases similar to 5% in the 650-850 degrees C temperature range. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.