Polymer composites embedded with low-dimensional materials for dielectric capacitors

Abstract

Dielectric capacitors can store energy by the displacement of bound charges, enabling rapid charging and discharging capability. In recent years, polymer-based dielectric capacitors have shown good characteristics in flexibility, lightweight, scalability, and low-cost for various energy storage applications. Specifically, they have high electric breakdown thresholds (100 MV/m to GV/m) as compared to those of traditional ceramic capacitors (below 50 MV/m) but their energy density is constrained due to low dielectric permittivity (~ 2.2). Recent efforts incorporat inorganic nanomaterials for high permittivity with minimal compromises on the dielectric loss and the charging-discharging efficiency. Specifically, this work focuses on capacitors with enhanced energy storage performances by using low-dimensional 0-D, 1-D, 2-D, and multi-D materials, including artificial and biopolymer composites. The influences of interface effects and architectural designs for the energy density and breakdown strength are discussed in detail, such as structural orientation, surface functionalization, cross linking, core shell, and multilayer structures. A range of challenges and opportunities for future advancement have been summarized toward practical implementation of dielectric capacitors in pulsed power applications.