Quantitative analysis of microstructure and its related electrical property of SOFC anode, Ni–YSZ cermet

The microstructural and electrical properties of Ni–YSZ composite anode of solid oxide fuel cells (SOFC) were investigated. We measured the electrical conductivity via 4-probe DC technique as a function of Ni content (10–70 vol.%) in order to examine the correlation with the microstructure of Ni–YSZ cermet. Image analysis based on quantitative microscopic theory was performed to quantify the microstructure of Ni–YSZ composite. The size and distribution, contiguity and interfacial area of each phase or between the phases could be obtained from the image analysis. According to image analysis, contiguity between the same phases was simply dependent on the amount of that phase itself while the contiguity between different phases was greatly influenced by the amount of Ni phase because the overall microstructural changes were mainly controlled by the coarsening of Ni phase. These similarly quantified microstructural properties were used for the characterization of the electrical properties of Ni–YSZ cermet.