The Rectification Properties of an Electrode-Electrolyte Interface Operated at High Sinusoidal Current Density

The rectifying properties of a stainless steel/saline electrode-electrolyte interface were investigated using sinusoidal current (100, 1000, and 10 000 Hz) of increasing current density. The series-equivalent resistance, capacitance, and impedance were determined versus current density. At each frequency, with increasing current density, it was found that above a critical current density, the capacitance increased, the resistance and impedance decreased then increased. The current density for these transitions were higher as the frequency was increased. There was a threshold (peak-to-peak) current density for rectification, being 3.2, 30 and 390 mA/cm
²
for 100, 1000, and 10 000 Hz, respectively. The most sensitive indicator of approaching rectification was the increase in capacitance of the electrode-electrolyte interface with increasing current density.