EN
The main aspects of the cathode materials
morphology for Intermediate Temperature Solid Oxide Fuel
Cells (IT SOFC) are considered in this paper. The approaches
for estimation of their basic properties, e.g. oxygen mobility
and surface reactivity, are described and the results
of different techniques (e.g. weight and conductivity
relaxation, oxygen isotope exchange) application for studies
of powders and dense ceramic materials are compared.
The Ruddlesden-Popper type phases (e.g. Pr2NiO4) provide
enhanced oxygen mobility due to cooperative mechanism
of oxygen interstitial migration. For perovskites, the oxygen
mobility is increased by doping, which generates oxygen
vacancies or decreases metal-oxygen bond strength. Nonadditive
increasing of the oxygen diffusion coefficients
found that for perovskite-fluorite nanocomposites, it can be
explained by the fast oxygen migration along perovskitefluorite
interfaces. Functionally graded nanocomposite
cathodes provide the highest power density, the lowest
area specific polarization resistance, and the best stability
to degradation caused by the surface layer carbonization/
hydroxylation, thus being the most promising for thin film
IT SOFC design.