This contributed volume presents multiple techniques for the synthesis of nanodielectric materials and their composites and examines their applications in the field of energy storage. It overviews various methods for designing these materials and analyses their properties such as mechanical strength, flexibility, dielectric as well as electrical performances for end-user applications such as thin-film flexible capacitors, advanced energy storage capacitors, and supercapacitors. The book gives a special focus on examining the dielectric properties of polymer-based nanomaterials, core-shell structured nanomaterials, and graphene-based polymeric composites among others, and explains the importance of their use in the aforementioned energy storage applications. It provides a great platform for understanding and expanding technological solutions needed for global energy challenges and it is of great benefit to industry professionals, academic researchers, material scientists, engineers, graduate students, physicists, and chemists working in the area of nanodielectrics.