Polymer electrolytes: evolution, challenges, and future directions for lithium-ion batteries

Abstract

Electrolytes are indispensable in the field of energy storage and generation. Many types of electrolytes are currently available for various purposes. This review paper explains the various existing polymer electrolytes and the methodologies involved in their preparation. The evolution, history, classification and applications of polymer electrolytes in different fields are reviewed. The properties, like ionic conductivity, electrochemical stability, thermal stability and mechanical strength, needed for an ideal polymer electrolyte are critically explored. Also, the influence of the dielectric constant and temperature over the ionic conductivity of the polymer electrolytes and the necessary properties for an ideal polymer electrolyte are elucidated. In addition, the Arrhenius and Vogel–Tammann–Fulcher ion transport models are demonstrated and analysed to explain the ion conduction mechanisms of polymer electrolytes. Moreover, characterization techniques like electron impedance spectroscopy, transference number measurement and voltammetry for investigating the essential properties of the polymer electrolytes are discussed.