Low-temperature preparation by polymeric complex solution synthesis of Cu–Gd-doped ceria cermets for solid oxide fuel cells anodes: Sinterability, microstructures and electrical properties

A homogeneous dispersion of fine CuO in a gadolinia-doped ceria (CGO) ceramic matrix by the polymeric organic complex solution method has been achieved. Highly sinterable powders were prepared by this method after calcining the precursor at 600 °C and attrition milled. The powders consist of individual particles of few tens of nanometer in size with a low agglomeration state. The isopressed compacts were sintered in air at 1000 °C and reducing in N2 90%–H2 10% atmosphere to form Cu–CGO cermets. The microstructures showed a uniform distribution of porous metallic Cu particles surrounded by microporous spaces. The influence of Cu content in Cu–CGO cermets on the electrode performance has been investigated in order to create the most suitable microstructure. The electrical properties of Cu–CGO cermets have been also studied using impedance spectroscopy, in the temperature range form 150 to about 700 °C in argon atmosphere. These measurements determined a high value of electrical conductivity at 700 °C, similar to that corresponded to pure metallic cupper.