Methyl Methacrylate-co-glycidyl Methacrylate-Based Dielectric Films with High Breakdown Strength and Discharge Energy Density Tailored by PVDF

Abstract

Linear dielectric polymers are potential candidates for electrostatic capacitors due to their high breakdown strength, high efficiency, and low dielectric loss. In this work, a novel poly (vinylidene fluoride) (PVDF) tailored linear PMMA-co-GMA (MG) copolymer-based all-organic dielectric film with high breakdown strength and discharge energy density was prepared by the solution blending method. Compared with the PMMA homopolymer, the MG copolymer behaved with a higher energy density (5.6 J/cm3) since the GMA component bestowed higher polarity and yielded deep traps for the copolymer. On the other hand, the introduction of PVDF into MG further improved the dielectric constant and overcame the brittleness of MG films. When the concentration of PVDF was 30 wt %, the MG/PVDF film exhibited a high discharged energy density of 10.8 J/cm3 at 600 MV/m with a 78.7% discharge efficiency, which was 2.5 times that of pure PVDF (4.3 J/cm3 at 320 MV/m) and 1.9 times that of pure MG (5.6 J/cm3 at 460 MV/m). The improvement in energy storage performance might be ascribed to the excellent thermodynamic miscibility and hydrogen bond interaction between the linear MG copolymer and the ferroelectric PVDF. This research provides a new and feasible strategy for designing all-organic dielectric films with high energy density for energy storage applications.

Crosslinking modification and hydrogen bonding synergy to achieve high breakdown strength and energy density of PMMA-co-GMA/PVDF dielectric composite films

“…38 In addition, PEA/MG-30%PVDF has the highest breakdown strength, which may be attributed to its high content of hydrogen bonds. 42 The E b of the cross-linked composites decreased when the PVDF content was further increased, which was caused by the decrease in the hydrogen bond content. 42 Compared with other composite films, the PEA/MG-30%PVDF film has a higher b value (22.3), which indicates a stable breakdown strength.…”

“…42 The E b of the cross-linked composites decreased when the PVDF content was further increased, which was caused by the decrease in the hydrogen bond content. 42 Compared with other composite films, the PEA/MG-30%PVDF film has a higher b value (22.3), which indicates a stable breakdown strength. The leakage current density is shown in Fig.…”

“…Second, multiple hydrogen bonds are formed among composite materials. [30][31][32][37][38][39][40]42 The hydrogen bond can be used as a capture site for carriers, and conduction loss can be suppressed. 38 In addition, PEA/MG-30%PVDF has the highest breakdown strength, which may be attributed to its high content of hydrogen bonds.…”

All-organic PVDF-based composite films with high energy density and efficiency synergistically tailored by MMA-co-GMA copolymer and cyanoethylated cellulose

“…26 Compared with PMMA, the MMA- co -GMA (MG) copolymer has a higher dielectric constant and stronger electric breakdown strength, and is miscible with PVDF, resulting in a greater improvement of crystal morphology and U e of PVDF. 27,28 As a result of our previously published research, the introduction of MG into PVDF promoted the formation of hydrogen bonds, which was useful for enhancing the trap energy level due to the epoxy groups of GMA on the MG macromolecular chains, thus inhibiting the carrier's transportation and delivery. 27 Therefore, the E b and U e of the composites reached the maximum when PVDF was blended with MG at 40% content.…”

“…27,28 As a result of our previously published research, the introduction of MG into PVDF promoted the formation of hydrogen bonds, which was useful for enhancing the trap energy level due to the epoxy groups of GMA on the MG macromolecular chains, thus inhibiting the carrier's transportation and delivery. 27 Therefore, the E b and U e of the composites reached the maximum when PVDF was blended with MG at 40% content. 28…”