Model gauze electrode O2,Pt/O2-:: Effect of the cell's pretreatment and the single-crystal electrolyte orientation

The polarization resistance of a model platinum gauze electrode in contact with a single-crystal electrolyte of doped zirconium dioxide is studied by impedance spectroscopy. Geometric characteristics of metal/electrolyte contact (contact area, triple-phase boundary length) are easily determined. The electrode pretreatment affects results of measurements in identical conditions. Cathodic and anodic polarizations increases its activity. The partial polarization resistance of a low-frequency relaxation process (R-2) alters jumpwise, which suggests that there exist an initial state and a state after a current treatment. During a prolonged storage, R-2 alters with time and tends to regain the initial state. The polarization resistance of the initial electrode depends on the electrolyte orientation. No such dependence is observed for the current-treated electrode.