Investigation On Anode Parameter Of Fabrication YSZ Electrolyte Films By Screen-Printing Technique

In this thesis YSZ (Yttria-stabilized Zirconia) electrolyte thin films and Sr-doped LaMnO₃ (La_0.7Sr_0.3MnO₃, LSM) cathode were fabricated on different anode substrates by screen-printing technique, and the influence of different anode substrates on the output performance of single cell was investigated. Screen-printing technique for YSZ electrolyte films fabrication was optimized by changing the anode parameter to find the anode substrate that is optimal for screen-printing technique and improve the output performance of the single cell.Firstly, the influence of pore-former in anode substrate on single cell was investigated. The amount of TPB (Three-phase Boundary) in anode substrate was influenced by the amount of pore-former, and the output performance of single cell also was influenced by the amount of pore-former. The experiment result indicated that adding 20 wt% flour as pore-former in anode substrate was suitable. At 700℃, the power density of C20, in which 20 wt% pore-former was added into anode substrate, was 0.58 W/cm², and the power density of C0, with no pore-former in anode, was 0.14 W/cm²The particle size of NiO which synthesized by co-precipitation method was very small, and it was increased by pre-calcining NiO powder at different temperature. The pre-calcined NiO powder at different temperature was used as anodic raw material, by adding the same amount pore-former. With the pre-calcining temperature increased, the porosities decreased gradually. Porosity of anode was adjusted by NiO powder with different particle size. Different porosity means different output performance. The porosity of anode with pre-calcined NiO at 800℃was 28.7% after sintering at 1400℃and the power density of the corresponding single cell (Cell800) was 0.95 W/cm² at 700℃, which was higher than other cells.The weight ratio of NiO and YSZ in anode would influence the amount of TPB, and the weight ratio of NiO and YSZ in anode was changed. With the weight ratio of NiO increased, the conductivity of anode increased, and when the weight ratio of NiO and YSZ was 6:4, the conductivity reached 1429 S/cm. The power density of Cell6 was 1.17 W/cm² at 700℃, and it was higher than the single cell with other weight ratio in anode. So the suitable weight ratio of NiO and YSZ was 6:4.