YSZ thin films deposited by spin-coating for IT-SOFCs

Dense and crack-free yttria stabilized zirconia (YSZ) thin films were fabricated using a spin-coating technique for intermediate temperature solid oxide fuel cells (IT-SOFCs). The film thickness was greatly affected by spinning speed and coating cycles. The morphology of the films was investigated with scanning electron microscope. With cathodes consisting of yttria-stabilized bismuth oxide and sliver, anodes of samaria-doped ceria and nickel, the supported YSZ films were characterized as electrolytes for single cells with humidified hydrogen as fuel and stationary air as oxidant. Open circuit voltage was 1.08 V at 700 °C, close to the theoretical value and power density was 535 mW/cm2 at 750 °C and 400 mW/cm2 at 700 °C. Impedance analysis indicates that the performances of the SOFCs are determined essentially by the interfacial resistances, suggesting that optimizing the electrode materials are especially important for IT-SOFCs.