Polymer-Based Dielectrics with High Energy Storage Density

TLDR

Polymer film capacitors are essential in high‑power systems, but conventional polymer dielectrics have low energy density, causing them to occupy large volume in the overall electrical system. This review examines recent advances in polymer dielectrics aimed at achieving high energy storage density to reduce the weight and volume of polymer film capacitors. The energy density increase is achieved by developing novel high‑polarization polymers with optimized dielectric responses, creating nanocomposites of polymer matrices with high‑breakdown inorganic fillers, and employing state‑of‑the‑art low‑cost, high‑throughput manufacturing methods. These strategies have yielded maximum energy densities exceeding 30 J cm⁻³, at least five times higher than conventional polymer dielectrics.

Abstract

Polymer film capacitors are critical components in many high-power electrical systems. Because of the low energy density of conventional polymer dielectrics, these capacitors currently occupy significant volume in the entire electrical system. This article reviews recent progress made in the development of polymer dielectrics with high energy storage density, which can potentially lead to significant weight and volume reduction in polymer film capacitors. The increase in energy density is achieved through two approaches, namely (a) the development of novel polymers with high electric polarization and optimized dielectric responses and (b) the development of nanocomposites containing polymer matrixes with high breakdown strength and inorganic nanofillers with high polarization. Promising progress has been made through both strategies, resulting in a maximum energy density of >30 J/cm 3 , which is at least 5 times higher than those of conventional polymer dielectrics. The state-of-the-art manufacturing method for low-cost, high-throughput production of polymer films is also reviewed.