Polymers are one of the key elements in energy harvesting and storage devices due to their unique properties such as high breakdown strength, flexibility, ease of processing, and low cost, in comparison with traditional ceramic and metallic materials. Today, functional polymer composites have found an increasing number of applications; for example, polymer based dielectric capacitors are widely applied in electric transport, high power electronics, artificial skins, muscles, and flexible electronics, due to their advantages of having a high power density, high efficiency, stability, and low cost compared with other energy storage devices, such as lithium batteries, supercapacitors, and solar fuels.

In order to achieve improved properties for such applications, a wide variety of polymer based composite systems are being explored. They are based on a polymer matrix containing organic, ceramic, and carbon-based fillers that can either be randomly dispersed, aligned, or ordered in a multilayer form. There are also a lot of unclear issues that need to be explored, such as the mechanism of polarization in dielectrics, the essence for superhigh energy density, and the device applications.

This special issue aims to identify the topic of polymer based dielectric materials and their applications and welcomes original research and review articles.

Potential topics include but are not limited to the following:

• Electroactive polymers
• Chemistry, physics, and mechanism of polymer based dielectrics
• Composition, structure, and properties of polymer based dielectrics
• Interfaces in polymer based dielectric composites
• Fabrication and testing methods of polymer based dielectric composites
• High permittivity polymer based composites
• High voltage polymer based composites
• High energy storage density polymer based dielectrics capacitors