Fabrication of Thin-Film Yttria-Stabilized Zirconia Electrolyte by Aerosol-Assisted Chemical Vapor Deposition

Solid oxide fuel cells (SOFCs) are one of the most promising fuel cells because of their cost-effective materials, high efficiency, and fuel flexibility. However, the high operating temperature of SOFCs (>800°C) hinders their practical use. Performance enhancement by reducing the electrolyte thickness using thin-film deposition techniques may solve this drawback, because the large ohmic resistance of ion transport through the solid electrolyte lattice is the main factor increasing SOFCs’ operating temperature; this can be dramatically decreased with a thin electrolyte. Aerosol-assisted chemical vapor deposition (AACVD) uses aerosol droplets to transport high-mass precursors with reactive carrier gases. AACVD provides the opportunity to produce multicomponent materials at higher deposition rates with a cost-effective system compared to other thin-film deposition techniques. In this work, fully dense thin yttria-stabilized zirconia (YSZ) electrolyte films less than 1 μm thick were successfully fabricated by AACVD on the anode-supported SOFCs. For the AACVD, Zr(acac)₄ (acac=acetylacetonate) and Y(acac)₃ precursors were used as a solution in ethanol. High-purity N₂ was used as the carrier gas, and the substrates were heated to 450°C during the deposition. As a result, good fuel cell performance with a maximum power of 80‒590 mW/cm² was obtained at 450‒600°C. The details of the microstructures of our films and cells, together with the electrochemical performance evaluated from SOFCs with these AACVD YSZ electrolytes, will be presented at the session.