Evaluation of Mobility, Diffusion Coefficient and Density of Charge Carriers in Ionic Liquids and Novel Electrolytes Based on a New Model for Dielectric Response

Abstract

Ionic conductors are key components for many electrochemical applications, mainly in the field of energy conversion, for example, in photo-electrochemical (PEC) solar cells and fuel cells, in energy storage devices like batteries and in other technological applications like electro-chromic devices, super-capacitors, electrochemical sensors [1,2], separation membranes [3], new types of memory and computer architecture as well as in biomedical applications [4,5]. In the last few decades ionic conductors have gained a revolutionary development owing to intense research inspired by their potential use in many electrochemical device applications. However, improved electrolytes are necessary in order to optimize the performance of the device applications. Hence, the need for new electrolytes with improved property regarding conductivity, stability, durability and operating temperature range has called for solutions involving ionic liquids in solid or gel polymer electrolytes. The enormous number of research articles published in this field proves the broadening of a worldwide research interest on these materials. However, despite the present outstanding development of electrolyte materials, most of the theoretical advancement in this field goes far back, nearly half a century. Hence, to develop theories applicable for these newly developed electrolytes as well as for traditional electrolytes is vitally important for the advancement of the field. The most important property of an electrolyte is the ionic conductivity, ┫dc, and that of an ionic conductor containing many ionic species can be described by,