Editorial: Dielectric materials for electrical energy storage

Abstract

High-power energy storage systems have important applications in electrical grid, electric vehicles, nuclear, aerospace, telecommunication, military, defense and medical fields. The fast development of these equipment and devices drives the demand of new dielectric materials with high electrical energy storage capability. Taking an electrostatic capacitor as an example, its energy storage capability (U) is generally dependent on the dielectric constant (e) of the dielectric and the maximum electric field which the dielectric can withstand, and can be express as U = ∫ EdD = ∫ Ed(eοe· E), where e0 is the vacuum dielectric constant, E and D are the electric field applied on the dielectric and electric displacement, respectively. For a linear dielectric where the dielectric constant is independent of the electrical field, the energy storage capability can be simply expressed as U= 1/2;e0eE2. Therefore, one may increase the energy density of dielectric materials via enhancing the dielectric constant and/or breakdown strength of the dielectric materials.