Concepedia

High‐Energy‐Density Dielectric Polymer Nanocomposites with Trilayered Architecture

Feihua Liu, Qi Li, Jin Cui, Zeyu Li, Guang Yang, Yang Liu, Lijie Dong, Chuanxi Xiong, Hong Wang, Qing Wang

Advanced Functional Materials · 2017 · 421 citations · 42 references

TL;DR

The development of advanced dielectric materials with high electric energy densities is crucial for modern electronics and electric power systems. The study presents a new class of multilayer‑structured polymer nanocomposites with high energy and power densities and examines how filler content influences electrical polarization, breakdown strength, and energy density. The trilayered structure uses boron nitride nanosheets in PVDF outer layers for high breakdown strength and PVDF with barium strontium titanate nanowires in the central layer for a high dielectric constant, and simulations model electrical tree formation to verify experimental breakdown results. The optimized trilayered composite achieves a discharged energy density of 20.5 J cm⁻³ at a Weibull breakdown strength of 588 MV m⁻¹, a power density of 0.91 MW cm⁻³—over nine times that of commercial biaxially oriented polypropylene—and establishes a new design paradigm for high‑performance dielectric polymer nanocomposites.

Abstract

The development of advanced dielectric materials with high electric energy densities is of crucial importance in modern electronics and electric power systems. Here, a new class of multilayer‐structured polymer nanocomposites with high energy and power densities is presented. The outer layers of the trilayered structure are composed of boron nitride nanosheets dispersed in poly(vinylidene fluoride) (PVDF) matrix to provide high breakdown strength, while PVDF with barium strontium titanate nanowires forms the central layer to offer high dielectric constant of the resulting composites. The influence of the filler contents on the electrical polarization, breakdown strength, and energy density is examined. Simulations are carried out to model the electrical tree formation in the layered nanocomposites and to verify the experimental breakdown results. The trilayered polymer nanocomposite with an optimized filler content displays a discharged energy density of 20.5 J cm −3 at Weibull breakdown strength of 588 MV m −1 , which is among the highest discharged energy densities reported so far. Moreover, the nanocomposite exhibits a superior power density of 0.91 MW cm −3 , more than nine times that of the commercially available biaxially oriented polypropylene. The findings of this research provide a new design paradigm for high‐performance dielectric polymer nanocomposites.