Effect of impurities on structural and electrochemical properties of the Ni–YSZ interface

The changes in interface structure and chemical composition of a 99.995% pure nickel/yttria-stabilised zirconia (YSZ) interface were examined after heat treatment at 1000 °C in 97% H2/3% H2O with and without polarisation. Impedance spectroscopy was used for electrochemical characterisation. The results were compared to earlier investigations of a less pure nickel/YSZ interface. re interface developed different structures depending on whether or not the samples were polarised. Despite the purity of the nickel, impurities were found in the interfacial region. The pure electrodes/interfaces showed area specific polarisation resistances 10 times lower than the impure interfaces.