High pressures as an effective tool to separate different contributions to the electrode polarization of polar liquids and solids

Abstract

Electrode polarization effects are an important issue in electrochemistry. Here we report investigation of electrode polarization effects in ethanol (used as a model material), in solid and liquid phases at high pressures. Application of pressure has dramatic effect on electrode polarization. Firstly, it significantly reduces the fractional power exponent, which dominates the low-frequency electrode polarization impedance, from approximately 1 at ambient pressure to less than 0.1 at 1.3 GPa. At pressure we can observe transition of electrode polarization impedance from fractional frequency law to inversely proportional to frequency relationship. This transition observed for the first time solves the problem with analytical limitation of electrode polarization effects at higher frequencies. Experimental data fitting by the procedure proposed by us, enables extracting the temperature dependencies of dielectric constant and dielectric relaxation frequency in the solid phase of ethanol at high pressures.