Energy Density Of Polymer Nanocomposites Research Articles

Optimizing the dielectric constant of the shell layer in core-shell structures for enhanced energy density of polymer nanocomposites.

Improved dielectric constant and breakdown strength facilitates excellent energy storage density of polymer dielectrics, which is positive to miniaturize dielectric capacitors in electronic and electrical systems. Although coating polar substances on nanoparticles enhances the dielectric constants of polymer nanocomposites, it usually causes local electric field concentration, leading to poor breakdown strength. Here, fluoropolymers with tailorable fluorine content (PF0, PF30 and PF60) are coated on BaTiO3 (BT) nanoparticles to construct typical core-shell structures that are further blended with poly(vinylidenefluoride-co-hexafluoropropylene) (P(VDF-HFP)) to obtain BT@PF/P(VDF-HFP) nanocomposites. Uniform dispersion of nanoparticles and excellent compatibility of interfaces are observed for the samples. In addition, the dielectric constant gradually increases from 8.03 to 8.26 to 9.12 for the nanocomposites filled with 3 wt% BT@PF0, BT@PF30 and BT@PF60, respectively. However, 3 wt% BT@PF30/P(VDF-HFP) has the highest breakdown strength (455 kV mm-1) among the nanocomposites, which is as good as neat P(VDF-HFP). More importantly, BT@PF30 rather than BT@PF60 possesses the maximum discharged energy density (11.56 J cm-3 at 485 kV mm-1), which is about 1.65 times that of neat P(VDF-HFP). This work proposes a facile experimental route to optimize the dielectric constants of the shell layer to couple the dielectric constants between the nanoparticles, shell layer and polymer matrix, which contributes to alleviating the local electric field concentration for excellent breakdown strength and electrical energy storage of polymer nanocomposites.

Coating Fluoropolymer on BaTiO3 Nanoparticles to Boost Permittivity and Energy Density of Polymer Nanocomposites

Significantly enhanced dielectric constant and energy storage density positively facilitate miniaturising dielectric capacitors for various applications in electronics and electrical devices. Herein, a fluoropolymer is coated on BaTiO3 (BT) nanoparticles to form a core–shell structure (BT@PF80), which is used as additional dipoles to enhance the dielectric constant and energy density of polymer nanocomposites. Characterizations with various techniques show uniform dispersion of nanoparticles and good compatibility of interfaces in polymer nanocomposites. Furthermore, the dielectric constant increases from 7.85 of neat polymer to 9.43 of the nanocomposites filled with BT@PF80 while the dielectric loss further decreases from 0.05 to 0.04 at 1 KHz. In addition, 7.79 J cm−3 of energy density is achieved at the nanocomposites filled with BT@PF80, which is 2.65 times higher than that of the neat polymer. This work presents a simple and effective means to enhance dielectric constant and energy density, which tends to fertilize the fabrications of polymer dielectrics for electric energy storage.

Ultrahigh energy density of polymer nanocomposites containing electrostatically self-assembled graphene oxide and hydrotalcite nanosheets

In this paper, the nanofiller consisting of graphene oxide (GO) and organically modified hydrotalcite (HT) was fabricated via the electrostatic self-assembly and further reduced and incorporated into the polyimide (PI) matrix to prepare superior nanocomposite films with high energy storage density. It was observed by transmission electron microscopy (TEM) that the insulating HT facesheets were attached well onto the GO film to form a stable sandwich structure. The synthesized ternary nanocomposite film (1.0 rGO@HT/PI) showed high breakdown strength of 175.9 kV/mm and ultra-high dielectric constant at 10 kHz (εr = 35.4), about 10 folds more than pure PI (εr = 3.4), resulting in a maximum energy storage density of 4.84 J/cm3. On account of electrostatic self-assembly, HT nanosheets can efficiently reduce the contact area between graphene oxides and inhibit the formation of conductive networks, thus maintaining a high level of breakdown strength and increasing the energy storage density of the nanocomposite films.

Large enhancement of discharge energy density of polymer nanocomposites filled with one-dimension core-shell structured NaNbO3@SiO2 nanowires

Design an architecture with the ability to improve breakdown strength has critical role to play for performance enhancement in energy storage capability. In this work, we report that the composite films with loaded with one dimension (1D) core-shell structured NaNbO3@SiO2 nanowires (NN@SiO2 NWs) are prepared and achieved significantly performance improvement in energy storage capability. The finite element simulation and experiment results both confirm the superiority of the 1D core-shell structured NN@SiO2 NWs in improving the energy density of the nanocomposite films. Especially, the nanocomposite films filled with 3 vol% NN@SiO2 NWs show a large discharged energy density of 12.1 J cm−3, which is ≈ 243% over the bare PVDF (4.98 J cm−3) and ≈ 1008% greater than biaxially oriented polypropylenes (BOPP) (≈ 1.2 J cm−3 at 640 MV m−1). Therefore, this nanocomposite film can be considered as potential high-performance dielectric materials for next-generation pulsed power capacitor applications.

Ultrahigh Breakdown Strength and Improved Energy Density of Polymer Nanocomposites with Gradient Distribution of Ceramic Nanoparticles

AbstractHigh‐energy‐density polymer nanocomposites with high‐dielectric‐constant ceramic nanoparticles as the reinforcement exhibit great potential for energy storage applications in modern electronic and electrical systems. However, the decline of breakdown strength by high loading of ceramic nanoparticles hinders this composite approach from sustainable promotion of energy density. In this work, an approach is proposed and demonstrated by constructing gradient distribution of the spherical ceramic nanoparticles in the polymer matrix. These gradient‐structured nanocomposites possess remarkably improved mechanical and electrical behaviors, which give rise to ultrahigh breakdown strength and much‐promoted energy density. Moreover, this enhancement effect can be further enlarged via increasing the grades number of gradient structures. This work provides an effective strategy for developing flexible high‐energy‐density polymer/ceramic nanocomposites for dielectric and energy storage applications.

Highly enhanced discharged energy density of polymer nanocomposites via a novel hybrid structure as fillers

Novel Ag@BaTiO3@PDA@Ag/P(VDF-HFP) composite films exhibited excellent discharged energy density (17.25 J cm−3) and ultrafast discharge time (∼139 ns).

High discharged energy density of polymer nanocomposites containing paraelectric SrTiO3 nanowires for flexible energy storage device

Nanocomposites combining high permittivity ferroelectric nanofillers and high breakdown strength polymer have shown tremendous potential for pulsed power applications. Nevertheless, the discharged energy density and efficiency of these nanocomposites filled with ferroelectric fillers are limited due to the large remanent polarization of ferroelectric fillers employed. Here, uniform elongated morphology paraelectric SrTiO3 nanowires fillers were synthesized via a special stirring hydrothermal method. The fabricated P(VDF-CTFE)-based nanocomposites containing 3 vol% paraelectric SrTiO3 nanowires exhibit an enhanced discharged energy density of 8.8 J/cm3 at 3381 kV/cm, which exceeds most of the current reports at the same electric field. By direct comparison study with ferroelectric BaTiO3 nanowires fillers, the results show paraelectric SrTiO3 nanowires can simultaneously improve the discharged energy density and efficiency more effectively. Such enhancement in energy storage performance can be attributed to the following reasons: (I) The enhanced breakdown strength, which resulted from the reduced inhomogeneous electric fields via adopting the SrTiO3 nanowires with lower permittivity. (II) The paraelectric phase SrTiO3 nanowires show little hysteresis behavior compared to ferroelectric phase BaTiO3 nanowires. This work is of critical significance in making advanced dielectric nanocomposites that are viable for energy storage devices in current electronic and electrical applications.

High discharged energy density of polymer nanocomposites induced by Nd-doped BaTiO3 nanoparticles

A flexible polymer nanocomposite has been developed via introducing Nd-doped BaTiO3 nanoparticles into the poly(vinylidene fluoride). This nanocomposite delivers a discharged energy density up to 12.5 J/cm3 under an electric field of 420 kV/mm with only a small loading of 1 vol.% Nd-BaTiO3. High discharged energy density, mechanical flexibility, light weight, ease fabrication and low cost makes it attractive for advanced microelectronics and electrical power systems. Our results demonstrate that ceramics with giant dielectric permittivity as viable fillers for polymer nanocomposite dielectrics with higher energy density.

Significantly improved dielectric properties and energy density of polymer nanocomposites via small loaded of BaTiO3 nanotubes

Flexible dielectric polymeric films are highly desirable materials with potential applications in power-conditioning equipment and pulsed-plasma thrusters due to their high dielectric constant, low dielectric loss, and fast energy uptake and delivery. In this work, 1–3 type nanocomposites combining BaTiO3 nanotubes (BT NTs) and poly(vinylidene fluoride) (PVDF) were prepared by a solution cast method. The BT NTs were synthesized by facile coaxial electrospinning and were coated with a dense and robust dopamine layer, which effectively improved the filler-matrix distributional homogeneity and compatibility. The 10.8 vol% BT-DA NTs/PVDF nanocomposites possessed an excellent dielectric constant of 47.05, which is approximately 569% greater that of the pristine PVDF (8.26) and 150%–350% higher than that of the other PVDF nanocomposites loaded with similar ceramic filler contents, e.g., nanoparticles, nanowires, and nanofibers. The highest energy density of 7.03 J cm−3 at a relatively low field of 330 MV m-1 was obtained via small loaded of the fillers, which is approximately 625% greater than for biaxially oriented polypropylenes (BOPP) (1.2 J cm−3 at the field of 640 MV m−1). The approach employed in this study may be further applied to the fabrication of similar polymeric nanocomposites for next-generation electronic components.

Enhanced energy density of polymer nanocomposites at a low electric field through aligned BaTiO3 nanowires

Significantly enhanced energy density is obtained at a low electric field by embedding aligned BaTiO3 nanowires in a polymer matrix via a new physical-assisted casting method.

High energy density of polymer nanocomposites at a low electric field induced by modulation of their topological-structure

High energy density at low electric field is achieved for polymer nanocomposites by modulating topological structure.

Tailoring Dielectric Properties and Energy Density of Ferroelectric Polymer Nanocomposites by High-k Nanowires.

High dielectric constant (k) polymer nanocomposites have shown great potential in dielectric and energy storage applications in the past few decades. The introduction of high-k nanomaterials into ferroelectric polymers has proven to be a promising strategy for the fabrication of high-k nanocomposites. One-dimensional large-aspect-ratio nanowires exhibit superiority in enhancing k values and energy density of polymer nanocomposites in comparison to their spherical counterparts. However, the impact of their intrinsic properties on the dielectric properties of polymer nanocomposites has been seldom investigated. Herein, four kinds of nanowires (Na2Ti3O7, TiO2, BaTiO3, and SrTiO3) with different inherent characteristics are elaborately selected to fabricate high-k ferroelectric polymer nanocomposites. Dopamine functionalization facilitates the excellent dispersion of these nanowires in the ferroelectric polymer matrix because of the strong polymer/nanowire interfacial adhesion. A thorough comparative study on the dielectric properties and energy storage capability of the nanowires-based nanocomposites has been presented. The results reveal that, among the four types of nanowires, BaTiO3 NWs show the best potential in improving the energy storage capability of the proposed nanocomposites, resulting from the most signficant increase of k while retaining the rather low dielectric loss and leakage current.

Fluoro-Polymer@BaTiO3 Hybrid Nanoparticles Prepared via RAFT Polymerization: Toward Ferroelectric Polymer Nanocomposites with High Dielectric Constant and Low Dielectric Loss for Energy Storage Application

Polymer nanocomposites with high energy density and low dielectric loss are highly desirable in electronic and electric industry. Achieving the ability to tailor the interface between polymer and nanoparticle is the key issue to realize desirable dielectric properties and high energy density in the nanocomposites. However, the understanding of the role of interface on the dielectric properties and energy density of polymer nanocomposites is still very poor. In this work, we report a novel strategy to improve the interface between the high dielectric constant nanoparticles (i.e., BaTiO3) and ferroelectric polymer [i.e., poly(vinylidene fluoride-co-hexafluoro propylene)]. Core–shell structured BaTiO3 nanoparticles either with different shell thickness or with different molecular structure of the shell were prepared by grafting two types of fluoroalkyl acrylate monomers via surface-initiated reversible addition–fragmentation chain transfer (RAFT) polymerization. The dielectric properties and energy storage c...