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 (R₂) alters jumpwise, which suggests that there exist an initial state and a state after a current treatment. During a prolonged storage, R₂ 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.