Polymer Electrolytes and their Composites for Energy Storage/Conversion Devices presents a state-of-the-art overview of the research and development in the use of polymers as electrolyte materials for various applications. It covers types of polymer electrolytes, ion dynamics, and the role of dielectric parameters and a review of applications. Divided into two parts, the first part of the book focuses on the types of polymer electrolytes, ion dynamics, and the role of dielectric parameters, while the second part provides a critical review of applications based on polymer electrolytes and their composites. This book: Presents the fundamentals of polymer composites for energy storage/conversion devices Explores the ion dynamics and dielectric properties role in polymer electrolytes Provides detailed preparation methods and important characterization techniques to evaluate the electrolyte potential Reviews analysis of current updates in polymer electrolytes Includes various applications in supercapacitor, battery, fuel cell, and electrochromic windows The book is aimed at researchers and graduate students in physics, materials science, chemistry, materials engineering, energy storage, engineering physics, and industry.