Anodic Performance of Ni–BCZY and Ni–BCZY–GDC Films on BCZY Electrolytes

Cermet films consisting of Ni, BaCe0.4Zr0.4Y0.2O3−δ (BCZY), and Gd0.1Ce0.9Ox (GDC), specifically, 60 wt%Ni–BCZY, 60 wt%Ni–BCZY–GDC, and 60 wt%Ni–GDC, were formed on BCZY electrolyte supports as anodes of proton ceramic fuel cells (PCFCs). The Ni grain size in these films after sintering at 1450 °C was around 2 μm. The GDC addition did not affect the Ni grain size in the case of the BCZY matrix. The anodic properties greatly depended on the oxide phase composition and worsened with increasing the GDC content. This probably occurred because of the addition of GDC, which has low proton conductivity and inhibited the proton conduction path of BCZY, reducing three-phase boundaries in the anode bulk. Since BCZY has a lower grain growth rate during sintering than BaCe0.8Y0.2O3−δ, the Ni grain growth was likely suppressed by the surrounding Ni grains containing small BCZY grains.