Analytical analysis of concentration of charge carriers in polymer electrolytes through different models

Abstract

The development of solid polymer electrolytes with high ionic conductivity and good chemical and mechanical stability for application in various electrochemical devices has been a critical area of research in the past few decades. For the better performance of the electrochemical devices, the compatibility between the electrodes and electrolytes of the system is the foremost requirement. In addition to this, the ion conductivity of the electrolytes is an important parameter. Understanding the mechanism of changes in ionic conductivity with different concentrations of salt and dispersoid is very crucial. In the present work, we have used three theoretical models, the Rice-Roth model, the Trukhan model and Schutt and Gerdes Model, to understand the reasons behind the variation in conductivity by calculating the concentration and mobility of charge carriers. All the required parameters of the model for the calculation purpose have been taken from Impedance Spectroscopy data. The Trukhan model is a direct method for evaluating the exact value of the diffusion coefficient. The diffusion coefficient of PEO-NaI based electrolyte thin films are calculated from the dielectric tangent loss and further used for analyzing the concentration of charge carrier and ion mobility. Similarly, two more theoretical models, Rice-Roth and Schutt & Gerdes model were used to confirm the value of the number of charge carriers. Further, all the results are compared with each other for the conclusion.