A Ferroconcrete‐Like All‐Organic Nanocomposite Exhibiting Improved Mechanical Property, High Breakdown Strength, and High Energy Efficiency

Abstract

Polymer‐based nanocomposite dielectrics with high energy storage capacity are crucial enablers for numerous applications in modern electronic and electrical industries. The energy density of parallel plate capacitors is determined by breakdown strength and dielectric permittivity of the inner dielectrics. Poly(vinylidene fluoride‐trifluoroethylene‐chlorofluoroethylene) (P(VDF‐TrFE‐CFE)), with the highest permittivity among all the dielectric polymers, is a promising candidate for high energy density capacitors. However, its relatively low breakdown strength and energy efficiency restrict the applications. In this work, a new method combining combinatorial‐electrospinning and hot‐pressing is proposed to fabricate P(VDF‐TrFE‐CFE)‐based all‐organic dielectrics with ferroconcrete‐like structure. In this structure, continuous fibers of polysulfone (PSF) with high Young's modulus act as tough scaffold to improve the mechanical properties of nanocomposites, and an over 750% enhancement of Young's modulus is obtained. The enhanced mechanical properties bring about significant improvement in Weibull breakdown strength to 485 MV m−1, more than 50% higher than neat terpolymer. Furthermore, the suppressed leakage current and conduction loss, and hence the improved discharge energy efficiency under moderate electric field, are achieved due to the high insulation of PSF and its interfacial restriction on space charge mobility.

Construction of porous poly (aryl sulfide sulfone) film with low dielectric constant and excellent mechanical property

“…The electrical breakdown strength is also an essential property of dielectric materials. Therefore, we tested the electrical breakdown performance of various PASS films and used the two‐parameter Weibull distribution function 49–53 to analyze the measured breakdown strength dat. Weibull distribution is often used in reliability evaluation to analyze the probability of material breakdown under a certain electric field strength or failure in a certain time.…”

Energy Storage Application of All-Organic Polymer Dielectrics: A Review

“…The combination of electrospinning and hot-pressing technology provides a new method for optimizing the energy density and breakdown strength of composite materials, allowing for the investigation of the relationship between the structure and properties of composites. Reprinted with permission from [132]. Copyright (2019), Wiley.…”

“…The breakdown strength of P(VDF-TrFE-CFE)/PSF was shown to initially increase and then decrease with increasing PSF content. As a result, nanocomposites containing 30 vol% PSF achieved a high Weibull breakdown strength of 485 MV/m, more than 50% higher than the neat terpolymer (~320 MV/m) ( Figure 13 b,c) [ 132 ].…”

“… ( a ) Schematic diagram of the composite film prepared by combinatorial-electrospinning and hot-pressing; ( b ) The Weibull distribution for P(VDF-TrFE-CFE)/PSF with various PSF contents; ( c ) The Weibull breakdown strength and shape parameter β as functions of PSF volume fractions. Reprinted with permission from [ 132 ]. Copyright (2019), Wiley.…”

Structure design boosts concomitant enhancement of permittivity, breakdown strength, discharged energy density and efficiency in all‐organic dielectrics

“…ferroconcrete‐like structure, promising for high energy density capacitor design. In previous research [42], we found that with proper design, this structure could bring about significantly improved mechanical property and enhanced breakdown strength. Herein, linear dielectric polymethyl methacrylate (PMMA) is chosen as the matrix, since its intrinsic high breakdown strength and high discharged energy efficiency.…”