Electrode Polarization of Ionic Conductors

Abstract

Polarization observed on applying ac and dc electric fields to samples of β alumina, sodalime glass, and single crystals of sodium chloride have been studied. It is concluded that the large capacitances shown by these materials, which are generally attributed to space-charge effects, are more likely caused by reactions at the electrodes which build up cell potentials. Electrochemical models, involving these cell potential effects, are presented and compared with previous space-charge models which have been applied to solid electrolytes.

Optical absorption in current-blackened yttria-stabilized zirconia

“…Evidence in earlier papers [1,2] indicates that electrons are injected into the crystal from the cathode, forming the centres which produce the darkened region, which has lower resistivity than the remainder, so that a virtual cathode [8] which leads to precipitation of finely-divided metal from the electrodes, and of sodalime glass [9], in which brown colouration is due to colloidal sodium metal.…”

AC and DC electrical conductivity in natural rubber/nanofibrillated cellulose nanocomposites

“…Under the application of an electric field the free charges drift towards the electrodes where they accumulate, leading to an apparent large macroscopic polarization of the material. This effect is well known in dielectrics possessing a certain amount of conductivity (mobile ions), such as ionic conductors [37][38][39] or colloidal suspensions [40]. It has also been observed in some polymers [41].…”

Thermal degradation analysis of thermoset resins

“…With the existence of nonnegligible conductivity, the low-frequency relaxation could be related to electrode polarization. 28 Electrode polarization usually leads to a very large (several decades) increase in E r when it is moving toward low frequencies. 28 Something similar was observed for all three thermoset systems.…”

“…28 Electrode polarization usually leads to a very large (several decades) increase in E r when it is moving toward low frequencies. 28 Something similar was observed for all three thermoset systems. 6,7,29 The developed DEA measurements were used to characterize (in a preliminary investigation) an EP composite (an EP-S 2 -glass composite) exposed to a high temperature (330 C) with the exposure time.…”

“…However, very few data were reported about the effects of high temperatures on the dielectric properties of thermoset resins. 27,28 In this effort, thermoset resins (BMI, EP, and VE resins) were exposed to temperatures well above the glass transition for a short period of time. The changes in the dielectric properties of the resins were studied to evaluate their sensitivity to thermal exposure and to predict the mechanical performance of heat-exposed resins.…”