Performance of tubular solid oxide fuel cell assembled with plasma-sprayed Sc₂O₃-ZrO₂ electrolyte

Ni-Al₂O₃ cermet supported tubular solid oxide fuel cell (SOFC) was fabricated by thermal spraying. The anode, electrolyte and cathode were deposited by plasma spraying and the Ni-Al₂O₃ cermet support was deposited by flame spraying to aim at reducing manufacturing cost. The test cell was assembled employing scandia stabilized zirconia (ScSZ) and yttria stabilized zirconia (YSZ) deposits as the electrolyte and influence of electrolytic Ohmic polarization on cell's performance was investigated. The results showed that the maximum output power density increased through reducing the electrolyte thickness and increasing the electrical conductivity of electrolyte. The maximum output power density reached 0.89 W/cm² with ScSZ electrolyte of 40 μm thick at 1000 °C in comparison of 0.76 W/cm² obtained with YSZ electrolyte. The present results clearly revealed that the controlling polarization was electrode polarization for the plasma-sprayed single cell assembled with a thin APS ScSZ electrolyte of 40 μm thick. This fact indicates that the design and preparation of effective electrode in the SOFC assembled using thin electrolyte are more important to improve cell performance.