Preparation of yttria-stabilized zirconia thin films on strontium-doped LaMnO3 cathode substrates via electrophoretic deposition for solid oxide fuelcells

A yttria-stabilized zirconia (YSZ) thin film on an La0.8Sr0.2MnO3 porous ca thode substrate was prepared, using electrophoretic deposition (EPD) to fab ricate a solid oxide fuel cell (SOFC). The electrical conductivity of an La 0.8Sr0.2MnO3 substrate is satisfactorily high at room temperature; therefor e, YSZ powder could be deposited electrophoretically onto an La0.8Sr0.2MnO3 substrate without any extra surface treatment, such as a metal coating. Su ccessive repetition of EPD and sintering was required to obtain a film with out gas leakage, because of the thermal expansion coefficient mismatch betw een the YSZ and the La0.8Sr0.2MnO3 substrate. On the other hand, the electr omotive force of the oxygen concentration in the cell that used YSZ film pr epared via EPD increased and attained the theoretical value when the number of deposition acid calcination cycles was increased. Six or more successiv e repetitions were required to obtain a YSZ film without gas leakage. A pla nar-type SOFC was fabricated, using nickel as the anode and YSZ film (simil ar to 10 pm thick) that had been deposited onto the La0.8Sr0.2MnO3 substrat e as the electrolyte and cathode, The cell exhibited an open circuit voltag e of 1.0 V and a maximum power density of 1.5 W/cm(2), Thus, the EPD method could be used as a colloidal process to prepare YSZ thin-film electrolytes for SOFCs.