Preparation of nano-structured Ni–Ce0.8Gd0.2O1.9 anode materials for solid oxide fuel cells via the water-in-oil (W/O) micro-emulsion route

Highly dispersed nano-crystalline NiO–Ce0.8Gd0.2O1.9 (GDC) anode powders were synthesized through a novel water-in-oil (W/O) micro-emulsion route, that has not been previously reported. The spherical-shaped NiO–Ce0.8Gd0.2O1.9 nano-powders exhibited a high degree of dispersion, and the morphology of the NiO–Ce0.8Gd0.2O1.9 particles was controlled by varying the aqueous to oil phase ratio. The polarization resistance at 800 °C with humidified H2 fuel and the activation energy of ME10 anode synthesized by the micro-emulsion method with the aqueous to oil phase volume ratios of 1:12 were 0.02 Ω cm2 and 0.55 eV, respectively, which were significantly lower than those of other Ni–ceria-based anodes. These properties contributed to a smaller particle size and better dispersion compared to conventional anode materials, leading to an increased number of reaction sites. In accordance with the polarization resistance results, single cells containing ME10 anodes exhibited a high maximum power density of 0.36 W cm−2 at 800 °C with humidified H2 fuel.