High‐Energy‐Density Dielectric Polymer Nanocomposites with Trilayered Architecture

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.

Enhancing Dielectric Performance of Poly(vinylidene fluoride) Nanocomposites via Controlled Distribution of Carbon Nanotubes and Barium Titanate Nanoparticles

“…The competition between such two factors varies with increasing the filler content, yielding the non-monotonic relationship between BDS and filler content. Similar variation trend of BDS with increasing the BT content was also reported in other BT filled polymer composites, which was ascribed to the more serious structural imperfection phenomena caused by the porosity, micron voids and cracks when a critical fraction of fillers are employed into 41,42 the polymer matrix.…”

Enhancing Dielectric Performance of Poly(vinylidene fluoride) Nanocomposites via Controlled Distribution of Carbon Nanotubes and Barium Titanate Nanoparticles

“…The competition between such two factors varies with increasing the filler content, yielding the non-monotonic relationship between BDS and filler content. Similar variation trend of BDS with increasing the BT content was also reported in other BT filled polymer composites, which was ascribed to the more serious structural imperfection phenomena caused by the porosity, micron voids and cracks when a critical fraction of fillers are employed into 41,42 the polymer matrix.…”

Three-phases Fe 3 O 4 @TiO 2 -P(VDF-HFP) composite films with high energy storage density at low filler fraction under low operating electric field

“…Additionally, the electrical conductivity of composites shown in figure 4 is also slightly increased with filler fraction increase, while no insulator-to-conductor transition has been occurred. It is worth noting that the filler fraction in this study is quite low (2 vol.%) compared with other reports [11,12,27,32], which might be the main reason for the small differences between the dielectric performances of FO (figures S6(a) and (b)) and FO@TO filled composite films.…”

Concurrently Achieving High Discharged Energy Density and Efficiency in Composites by Introducing Ultralow Loadings of Core–Shell Structured Graphene@TiO2 Nanoboxes

“…(c) Radar plots of P­(VDF-HFP)-PEI film and 0.5 wt % G@TiO 2 /P­(VDF-HFP)-PEI film. (d) Comparison of this work and previously reported results. ,,,− (e) Comparison of discharge energy density as a function of filler content of G@TiO 2 /P­(VDF-HFP)-PEI film and previous reported references. ,,,,,,,,,,− …”

“…On the contrary, the composites with nonlinear polymer matrix have high energy densities but unsatisfactory discharge efficiencies. In this work, an ultrahigh U d of 19.39 J/cm 3 is successfully achieved in the film with merely 0.5 wt % nanofillers, which is much lower than most of the so far reported results (Figure e). ,,,,,,,,,,− The low filler fraction can effectively hinder the undesired microstructure changes (e.g., voids, cracks, aggregation of filler, etc. ), which contributes to the high breakdown strength and high efficiency.…”

Enhancing Dielectric Performance of Poly(vinylidene fluoride) Nanocomposites via Controlled Distribution of Carbon Nanotubes and Barium Titanate Nanoparticles

“…The competition between such two factors varies with increasing the filler content, yielding the non-monotonic relationship between BDS and filler content. Similar variation trend of BDS with increasing the BT content was also reported in other BT filled polymer composites, which was ascribed to the more serious structural imperfection phenomena caused by the porosity, micron voids and cracks when a critical fraction of fillers are employed into 41,42 the polymer matrix.…”

Three-phases Fe 3 O 4 @TiO 2 -P(VDF-HFP) composite films with high energy storage density at low filler fraction under low operating electric field

“…Additionally, the electrical conductivity of composites shown in figure 4 is also slightly increased with filler fraction increase, while no insulator-to-conductor transition has been occurred. It is worth noting that the filler fraction in this study is quite low (2 vol.%) compared with other reports [11,12,27,32], which might be the main reason for the small differences between the dielectric performances of FO (figures S6(a) and (b)) and FO@TO filled composite films.…”

Concurrently Achieving High Discharged Energy Density and Efficiency in Composites by Introducing Ultralow Loadings of Core–Shell Structured Graphene@TiO2 Nanoboxes

“…(c) Radar plots of P­(VDF-HFP)-PEI film and 0.5 wt % G@TiO 2 /P­(VDF-HFP)-PEI film. (d) Comparison of this work and previously reported results. ,,,− (e) Comparison of discharge energy density as a function of filler content of G@TiO 2 /P­(VDF-HFP)-PEI film and previous reported references. ,,,,,,,,,,− …”

“…On the contrary, the composites with nonlinear polymer matrix have high energy densities but unsatisfactory discharge efficiencies. In this work, an ultrahigh U d of 19.39 J/cm 3 is successfully achieved in the film with merely 0.5 wt % nanofillers, which is much lower than most of the so far reported results (Figure e). ,,,,,,,,,,− The low filler fraction can effectively hinder the undesired microstructure changes (e.g., voids, cracks, aggregation of filler, etc. ), which contributes to the high breakdown strength and high efficiency.…”

Enhancing Dielectric Performance of Poly(vinylidene fluoride) Nanocomposites via Controlled Distribution of Carbon Nanotubes and Barium Titanate Nanoparticles

“…The competition between such two factors varies with increasing the filler content, yielding the non-monotonic relationship between BDS and filler content. Similar variation trend of BDS with increasing the BT content was also reported in other BT filled polymer composites, which was ascribed to the more serious structural imperfection phenomena caused by the porosity, micron voids and cracks when a critical fraction of fillers are employed into 41,42 the polymer matrix.…”

Three-phases Fe 3 O 4 @TiO 2 -P(VDF-HFP) composite films with high energy storage density at low filler fraction under low operating electric field

“…Additionally, the electrical conductivity of composites shown in figure 4 is also slightly increased with filler fraction increase, while no insulator-to-conductor transition has been occurred. It is worth noting that the filler fraction in this study is quite low (2 vol.%) compared with other reports [11,12,27,32], which might be the main reason for the small differences between the dielectric performances of FO (figures S6(a) and (b)) and FO@TO filled composite films.…”

Concurrently Achieving High Discharged Energy Density and Efficiency in Composites by Introducing Ultralow Loadings of Core–Shell Structured Graphene@TiO2 Nanoboxes

“…(c) Radar plots of P­(VDF-HFP)-PEI film and 0.5 wt % G@TiO 2 /P­(VDF-HFP)-PEI film. (d) Comparison of this work and previously reported results. ,,,− (e) Comparison of discharge energy density as a function of filler content of G@TiO 2 /P­(VDF-HFP)-PEI film and previous reported references. ,,,,,,,,,,− …”

“…On the contrary, the composites with nonlinear polymer matrix have high energy densities but unsatisfactory discharge efficiencies. In this work, an ultrahigh U d of 19.39 J/cm 3 is successfully achieved in the film with merely 0.5 wt % nanofillers, which is much lower than most of the so far reported results (Figure e). ,,,,,,,,,,− The low filler fraction can effectively hinder the undesired microstructure changes (e.g., voids, cracks, aggregation of filler, etc. ), which contributes to the high breakdown strength and high efficiency.…”