Modelling of electrical properties of Ni-YSZ composites

Ni-YSZ cermets with tailored microstructural characteristics are of interest in many solid-state electrochemical applications such as fuel cell electrode processes or oxygen sensors. In order to elucidate the role of microstructural parameters on overall Ni-YSZ electrical characteristics, different cermets were synthesized by the citrate–nitrate combustion route and their electrical characteristics were tested. The combustion derived samples exhibited fairly high electronic conductivity, even at a relatively low metal volume fraction of 24 vol.% of Ni. To determine the electrical conductivity behaviour of the composites in a broad range of metal content and its relation to material porosity, the general effective media approach and the sine-wave approximation were used, respectively.