Synthesis and characterization of morphologically tailored NiO-Ce _0.8Gd_0.2O_2-δ anode materials for solid oxide fuel cells: A micro-emulsion followed by solvothermal approach

NiO-Ce_0.8Gd_0.2O_2-δ cermet anode powders with flake-shaped particles have been synthesized using a unique micro-emulsion-mediated solvothermal process. With an increase in the amount of urea used as a precipitation agent, the particles change from plate to flake shape in a morphological transition. Well-developed flake-shaped anode powders can be obtained from 24 h of solvothermal treatment. The polarization resistance at 800° C in humidified H₂ and the activation energy of the anode synthesized with 1:4 salt to urea ratio and the solvothermal treatment duration of 24 h are 0.01 Ω cm² and 0.53 eV, respectively. In accordance with the polarization resistance results, a single cell with the MEST4 anode shows a high maximum-power density of 0.32 W cm^-2, at 800° C with a humidified H₂ fuel.