Achieving high electric energy storage in a polymer nanocomposite at low filling ratios using a highly polarizable phthalocyanine interphase

Abstract

Polymer nanodielectrics have become attractive for practical applications such as electric energy storage and electromechanical actuation. However, to enhance the apparent dielectric constant of polymer nanodielectrics, a significant amount (>30 vol %) of spherical particles needs to be incorporated into the polymer matrix. As a consequence, meltprocessing of polymer nanodielectrics into uniform thin films becomes difficult at such a high filler content, and electric breakdown strength will greatly decrease. In this work, we describe a three-phase composite approach towards high energy density nanodielectrics at low filling ratios. In this approach, a highly polarizable tetrameric metallophthalocyanine (TMPc) initiator is coated onto 68 nm BaTiO 3 nanoparticles, from which poly(methyl methacrylate) (PMMA) brushes are grafted using atom transfer radical polymerization for the nanoparticles to be uniformly dispersed in a poly(vinylidene fluoride-co-hexafluoropropylene) [P(VDF-HFP)] matrix. For comparison, two-phase P(VDF-HFP)/BaTiO 3 composites without the TMPc interfacial layer are also prepared. Owing to the high polarizability of the TMPc interface layer, the three-phase composite films exhibit higher dielectric constant and thus higher energy density than the two-phase composite films at volumefilling ratios below 5 vol %. Therefore, these high energy density three-phase nanodielectrics with a low filling ratio are promising for melt-processing into thin dielectric films.

Effect of variation of different nanofillers on structural, electrical, dielectric, and transport properties of blend polymer nanocomposites

“…The lower dielectric constant value supports the complete dispersion of nanofiller properly with the polymer salt matrix and can play its effective role in the enhancement of the ionic conductivity while the high dielectric constant nanofiller is unable to show its effectiveness in enhancing the conductivity and may be due to agglomeration of nanofiller. So, the overall high dielectric constant of the polymer nanocomposite is desirable for the fast ion transport [59]. Further insight into understanding the overall dielectric constant will be provided by the dielectric spectroscopy study which will be explored in detail in next section.…”

Influence of shell thickness on the dielectric properties of composites filled with Ag@SiO2 nanoparticles

“…Nan has fabricated Ag@C core-shell structure fillers and incorporated into epoxy. [27][28][29] However, most of the afore-mentioned methods to fabricate core-shell structure fillers are complicated and difficult to apply in large-scale production. 24,25 Lu reported TiO 2 @MWCNTs/PVDF composites, which presented higher dielectric constant and breakdown field and lower dielectric loss compared to pristine MWCNTs/PVDF composites.…”

Significantly Enhanced Breakdown Strength and Energy Density in Sandwich‐Structured Barium Titanate/Poly(vinylidene fluoride) Nanocomposites

“…The dramatic improvement of energy‐storage properties in sandwich‐structured BT/PVDF nanocomposites is attributed to the macrostructure design that has a strong influence on the electric field distribution. In Figure a and Figure S5 (Supporting Information), the result of finite element simulation shows the redistribution of applied electric field, which is caused by the difference of the dielectric constants among ceramic phases and polymer phases . Heterogeneous distribution of electric field can be apparently illustrated by the spacing of adjacent equipotential lines.…”