Electrophoretic Deposition of Gadolinium-doped Ceria as a Barrier Layer on Yttrium-stabilized Zirconia Electrolyte for Solid Oxide Fuel Cells

Replacing the electronically conductive (LaSr)MnO3 +/- (LSM) cathode in the LSM/yttrium-stabilized zirconia (YSZ) systemwith the mixed ion-electron conductive (MIEC) (LaSr)(CoFe)O3- will promote cathode performance in solid oxide fuel cells (SOFCs) significantly. However, a barrier layer between LSCF and YSZ is necessary for preventing chemical reaction between these two components. In this study, a gadolinium-doped ceria (GDC) barrier layer was deposited on the YSZ electrolyte by scalable and cost-effective electrophoretic deposition (EPD). Polypyrrole (PPy) was coated on the YSZ surface as the conductive agent. A highly compact GDC green layer was obtained by the EPD process in an ethanol-based suspension. GDC barrier layers ranging in thickness from 5 mu m to 8 mu m were successfully densified at temperatures as low as 1,300 degrees C. The performance of these cells was evaluated using a symmetrical cell configuration through electrochemical impedance spectroscopy (EIS). Ohmic resistance of the GDC barrier layer made by EPD versus the conventional spin-coating method was reduced by 0.09 cm(2) at 750 degrees C, which generally accounts for 30% of the total ohmic resistance for the electrode-supported fuel cells (0.30 cm(2)). This result suggests that EPD is a highly desirable method for efficiently manufacturing an electrolyte barrier layer with improved performance.