Bimetallic (Ni–Fe) anode-supported solid oxide fuel cells with gadolinia-doped ceria electrolyte

Abstract

Anode-supported solid oxide fuel cells (SOFC) comprising nickel + iron anode support and gadolinia-doped ceria (GDC) of composition Gd 0.1Ce 0.9O 2− δ thin film electrolyte were fabricated, and their performance was evaluated. The ratio of Fe 2O 3 to NiO in the anode support was 3 to 7 on a molar basis. Fe 2O 3 and NiO powders were mixed in the desired proportions and discs were die-pressed. All other layers were sequentially applied on the anode support. The cell structure consisted of five distinct layers: anode support – Ni + Fe; anode functional layer – Ni + GDC; electrolyte – GDC; cathode functional layer – LSC (La 0.6Sr 0.4CoO 3− δ ) + GDC; and cathode current collector – LSC. Cells with three different variations of the electrolyte were made: (1) thin GDC electrolyte (∼15 μm); (2) thick GDC electrolyte (∼25 μm); and (3) tri-layer GDC/thin yttria-stabilized zirconia (YSZ)/GDC electrolyte (∼25 μm). Cells were tested with hydrogen as fuel and air as oxidant up to 650 °C. The maximum open circuit voltage measured at 650 °C was ∼0.83 V and maximum power density measured was ∼0.68 W cm −2. The present work shows that cells with Fe + Ni containing anode support can be successfully made.