Supercapacitors are energy storing devices, gaining great scientific attention due to their excellent cycling life, charge-discharge stability, energy, and power density. The central theme of this book is to review the multiple applications of polymer nanocomposites in supercapacitors in a comprehensive manner, including discussions pertaining to various unresolved issues and new challenges in the subject area. It illustrates polymer nanocomposite preparation and working mechanisms as electrodes, binders, separators, and electrolytes. This edited volume also explains different components of supercapacitors, including theory, modelling, and simulation aspects. Features: Covers the synthesis and properties of polymer nanocomposites for varied usage. Explains roles of different types of nanofillers in polymeric systems for developing supercapacitors. Highlights theory, modelling, and simulation of polymeric supercapacitors. Gives an illustrative overview of the multiple applications of polymers and their nanocomposites. Includes graphene, CNT, nanoparticle, carbon, and nano-cellulose-based supercapacitors. This book is aimed at graduate students and researchers in materials science, polymer science, polymer physics, electrochemistry, electronic materials, energy management, electronic engineering, polymer engineers, and chemical engineering.