Coke-tolerant La₂Sn₂O₇-Ni-Gd_0.1Ce_0.9O_1.95 composite anode for direct methane-fueled solid oxide fuel cells

Direct CH₄-fueled solid oxide fuel cells (SOFCs) have been studied for a few decades, but carbon depositions on the Ni-based anodes are still remained as a major problem. In order to enhance coke tolerances and durability of SOFCs, La₂Sn₂O₇ nano-powders are prepared by co-precipitation. The SOFCs with the different amounts of the La₂Sn₂O₇ nano-powders in the Ni-GDC anodes are tested under dry CH₄, and the 0.3 wt.% La₂Sn₂O₇-Ni-GDC (0.3LNG) anodes show the highest cell performances of all anodes. The maximum power density of the cell is approximately 0.55 W cm⁻² at 650 °C. The durability of the 0.3LNG cell is significantly enhanced without any carbon formations, showing approximately 0.69 V over 600 h at 0.3 A cm⁻², whereas the conventional Ni-GDC cell is stopped only after 90 h. It suggests that the 0.3LNG is a promising anode material to enhance coke-tolerances and durability of direct-methane fuel cells.