Electrochemical performance of IT-SOFCs with a double-layer anode

A new type of anode with double layers, composed of an outer layer Ni-CeO2 (about 0.5 mm) with relatively large porosity and pore size and an inner layer adjacent to the electrolyte Ni-SDC (about 120 μm), was developed for direct utilization of methane fuel in low-temperature solid oxide fuel cells (SOFCs) with thin-film SDC electrolytes. Cells with this novel anode were fabricated using a tri-layer co-pressing technique. This anode microstructure is believed to lower the anodic concentration polarization when using methane as fuel. Impedance measurements show that the anode polarization resistance of the cell with the novel anode in H2 is only 0.02 Ω cm2 which is lower than a conventional Ni/SDC anode. However, it is about 0.2 Ω cm2 lower when using methane as fuel, which is consistent with the results of electrochemical measurements, inferring that the novel anode shows a relatively high catalytic activity towards methane than the conventional anode. The stability of the cell with the novel anode at 600 °C when using methane as fuel was also studied.