Laser machining of YSZ ceramics for solid oxide fuel cells (SOFC)

Summary form only given. Yttria stabilised zirconium oxide (YSZ) is a very important class of ceramic with unique mechanical and electrochemical properties. For this reason, YSZ is been widely used in oxygen sensors and solid oxide fuel cells (SOFC). Among the different SOFC configurations, the electrolyte-supported one exhibits better mechanical robustness and resistance to redox cycles than the electrode-supported configuration. However, its main inconvenience is that electrolyte-supported cells are prepared over 100-300 μm thick electrolytes and, as a consequence, they are designed to operate at high temperatures to reduce its ohmic resistance, typically about 900°C for YSZ electrolytes.The ability of YSZ ceramic to withstand precision machining would allow a different alternative, using laser machining, to prepare thinner self-supporting ionic conducting membranes. In the last few years, laser technology has shown very unique results for materials engraving. It allows a cost-efficient production for the fabrication of high quality ceramic parts with excellent shaping, accuracy and surface finishing [1]. The laser machining procedure yields to the fabrication of ceramics membranes from a thick and sintered ceramic plate. The original thick plate is engraved in the central part to obtain a thin region (around 20 μm), which is the electrochemically active area, while the surrounding part remains thick and acts as a mechanical support giving the membranes outstanding thermomechanical integration [2].