Enhanced Thermal Stability of Cu-Based SOFC Anodes by Electrodeposition of Cr

The electrodeposition of Cr onto Cu-based, solid oxide fuel cell (SOFC) electrodes was investigated. Cu–ceria–YSZ (yttria-stabilized zirconia) electrodes were prepared by impregnation of porous YSZ with aqueous solutions of and and modified by the addition of a Cr layer onto the Cu. The addition of Cr had no effect on anode performance at in humidified but significantly improved the thermal stability. Without Cr, scanning electron microscopy showed structural changes in the Cu films after heating to , resulting in increased ohmic resistances in impedance spectra. The addition of Cr increased thermal stability so that the anodes were unaffected by heating to in dry . Some oxidation of Cr was observed by X-ray diffraction following exposure of the composite to 80% mixtures at for , but partial oxidation of Cr did not affect the thermal stability of the anode. Exposure of the composite to 80% mixtures at for resulted in complete oxidation of the Cr and a loss of enhanced thermal stability. Attempts to prevent Cr oxidation by the electrodeposition of Cu onto the Cr were unsuccessful. Based on these results, strategies for enhancing the stability of Cu-based anodes are discussed.