Lanthanum Nickelate Infiltration into Porous Gd-Doped Ceria As Cathode for Solid Oxide Fuel Cells
In this study, cathodes were prepared by infiltration of lanthanum nickelate into a Gd-doped ceria (GDC) backbone sintered on 8YSZ electrolyte pellets. The influence of the preparation parameters of the composite electrodes on their electrochemical activity will be presented. The optimization of the preparation parameters led to a large decrease of the polarization resistance, down to 0.1 Ω·cm² at 600 °C. Using the Adler-Lane-Steele model, the impedance diagrams were fitted, allowing the determination of the surface exchange rate and ionic conductivity of the electrode: the obtained values well agree with those previously reported in the literature. Using this infiltration process, single cells were made starting from commercial half cells (Ni cermet/8YSZ), the cathode being the composite LNO/GDC. Voltammetry measurements showed power density higher than 1 W.cm-2 at 800°C.