Effect of YSZ electrolyte surface modification on the performance of LSM/YSZ composite cathode

In order to understand the effect of YSZ electrolyte surface morphology on the performance of LSM/YSZ composite cathode, the YSZ electrolyte surface is structured with an interlayer of YSZ by screen printing. Three different YSZ powders are used for screen printing: the as-received original powder, the high-energy milled fine powder, and the pre-sintered coarse powder. The morphologies of different YSZ powders, the microstructures of the modified YSZ interlayers, and half cells with LSM/YSZ composite cathode are studied with scanning electron microscope. The performance of the LSM/YSZ cathodes is characterized with ac electrochemical impedance spectroscopy by using symmetric cells at 700–800 °C and OCV in air. The results indicate that the polarization resistance is decreased when pre-sintered coarse YSZ powder is screen printed onto the YSZ electrolyte surface. This is attributed to the increase of the effective surface area of the YSZ electrolyte.