BaTiO 3 platelets and poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) hybrid composites for energy storage application
TL;DR: In this article, BaTiO3 platelets are used for the first time to incorporate into a polymer matrix for energy storage, which significantly improves the permittivities of the nanocomposites compared with the pure polymer matrix.
About: This article is published in Mechanical Systems and Signal Processing.The article was published on 2018-08-01. It has received 28 citations till now. The article focuses on the topics: Polymerization & Nanocomposite.
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TL;DR: In this article, a review aims at updating various studies to design BaTiO3@polymer/Fluoropolymer nanocomposites, to study their properties and performances and to supply their applications.
123 citations
TL;DR: In this article, a two-dimensional core-shell NaNbO3@Al2O3 platelets (2D NN@AO Ps) and poly(vinylidene-fluoride hexafluoropropylene) (P(VDF-HFP)), featuring excellent energy storage capability, high efficiency, and ultrafast discharge performance, are designed and fabricated.
Abstract: With rapid developments in the consumer electronics market, electrostatic capacitors need to store as much energy as possible within a rather restricted space. In this work, nanocomposite films combining two-dimensional core–shell NaNbO3@Al2O3 platelets (2D NN@AO Ps) and poly(vinylidene-fluoride hexafluoropropylene) (P(VDF-HFP)), featuring excellent energy storage capability, high efficiency, and ultrafast discharge performance, are designed and fabricated. Both the experimental results and finite element simulations confirm the superiority of these 2D NN@AO Ps nanocomposite films in improving the breakdown strength (Eb) and energy storage capability. In particular, the introduction of 3 vol% 2D NN@AO Ps results in much enhanced discharge energy density of 14.59 J cm−3 and outstanding discharge efficiency of 70.1% in NN@AO Ps/P(VDF-HFP) nanocomposite films, which is much greater than that of pure P(VDF-HFP) (7.74 J cm−3). The corresponding nanocomposite films exhibit excellent reliability in energy storage performance under consecutive cycling. Therefore, this research could reveal a new chapter in the study and application of polymer nanocomposites in energy-storage dielectric capacitors.
84 citations
TL;DR: In this article, BaTiO3/poly (vinylidene fluoride) (BT/PVDF) composites using two-dimensional (2-D) platelets were prepared and investigated.
37 citations
TL;DR: In this article, core-shell structured TiO2@HfO2 nanowire arrays with designable HfO 2 layer thicknesses were constructed by atomic layer deposition (ALD) method.
Abstract: In this paper, core-shell structured TiO2@HfO2 nanowire arrays with designable HfO2 layer thicknesses were constructed by atomic layer deposition (ALD) method. The effects of TiO2@HfO2 nanowire arrays filler and HfO2 thickness on dielectric and energy storage properties of polyvinylidene fluoride (PVDF) based nanocomposites were investigated. The HfO2 shell thicknesses were controlled via regulating the cycle times of ALD and increased from 2.4 nm to 5.4 nm with the cycle times increment from 13 times to 50 times. Owing to the ferroelectricity of the HfO2 and the hierarchical interfacial polarization originated from the multilevel interface in the composites, the permittivity of the TiO2@HfO2 nanowire array/PVDF nanocomposite with 50 deposition cycles reached 27.4 at 103 Hz, which was 105% larger than that of the TiO2 nanowire array/PVDF nanocomposite. Moreover, the maximal discharged energy density is 2.92 J/cm3 at a low electric field of 138 kV/mm, exceeding more than 97%.
22 citations
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TL;DR: In this paper, the authors focus on the important role and challenges of high-k polymer-matrix composites (PMC) in new technologies and discuss potential applications of highk PMC.
1,412 citations
TL;DR: Comparisons with model calculations indicate the important roles of nanoparticle percolation and porosity of the nanocomposites on the dielectric properties, and the calculated maximum energy densities indicate maximal extractable energy for two different particle volume fractions.
Abstract: The dielectric permittivity and electric breakdown strength of nanocomposites comprising poly(vinylidene fluoride-co-hexafluoro propylene) and phosphonic acid surface-modified BaTiO3 nanoparticles have been investigated as a function of the volume fraction of nanoparticles. The mode of binding of pentafluorobenzylphosphonic acid on the BaTiO3 particles was investigated using infrared and 31P solid-state nuclear magnetic resonance spectroscopy, and the phosphonic acid was found to form well ordered, tightly bound monolayers. The effective permittivity of nanocomposites with low volume fractions (<50%) was in good agreement with standard theoretical models, with a maximum relative permittivity of 35. However, for nanoparticle volume fractions of greater than 50%, the effective permittivity was observed to decrease with increasing nanoparticle volume fraction, and this was correlated with an increase in porosity of the spin-coated nanocomposite films. The dielectric breakdown strength was also found to decre...
762 citations
TL;DR: In this article, a set of ligands, each bearing an aliphatic octyl chain with a different terminal binding group, was used to modify the surface of barium titanate (BT) nanoparticles.
Abstract: Materials with high dielectric permittivity are important in electronic components such as capacitors, gate dielectrics, memories, and power-storage devices. Conventional highpermittivity materials such as barium titanate (BT) can be processed into thin films by using chemical solution deposition yielding a relative permittivity (er) of about 2500 and relatively low dielectric loss but require high-temperature sintering, which is not compatible with many substrate materials. Polymer-based dielectrics, such as biaxially oriented polypropylene (BOPP), have good processability with high dielectric strengths (∼ 640 V lm) suitable for high-energy-density capacitors, but the storage capacity (ca. 1–1.2 J cm) is limited by the low er (ca. 2.2) of these materials. [6] Various approaches to high-er materials based on nanocomposites containing metal particles or other conductive materials have been pursued. Such nanocomposites have afforded huge er values but the resulting materials are limited by the high-temperature processing required, high dielectric loss, or low dielectric strength. Polymer/ceramic nanocomposites in which high-er metal oxide nanoparticles such as BT and lead magnesium niobate–lead titanate (PMN–PT) are incorporated into a polymer host are of significant current interest. The combination of high-er nanoparticles with high-dielectric-strength polymer hosts offers the potential to obtain processable highperformance dielectric materials. Simple solution processing of BT particles in a polymer host generally results in poor film quality and inhomogeneities, which are mainly caused by agglomeration of the nanoparticles. Addition of surfactants, such as phosphate esters and oligomers thereof, can improve the dispersion of BT nanoparticles in host polymers and consequently the overall nanocomposite film quality. However, in such systems, residual free surfactant can lead to high leakage current and dielectric loss. Thus, approaches to bind surface modifiers to BT nanoparticles via robust chemical bonds are highly desirable. Ramesh et al. have reported on the use of trialkoxysilane surface modifiers for the dispersion of BT nanoparticles in epoxy polymer hosts resulting in nanocomposites with reasonably high er, up to 45. [12] With the objective of identifying ligands that can form stable bonds to a BT surface through coordination or condensation, we have investigated a series of different ligand functionalities. In this Communication, we report that phosphonic acid ligands effect robust surface modification of BT and related nanoparticles and that the use of particles modified with suitable phosphonic acid ligands leads to well-dispersed BT nanocomposite films with high er and high dielectric strength. We have investigated the binding of a variety of ligands to the surface of BT nanoparticles, as the stability of the binding on the surface is vital to effective surface modification. We examined the following set of ligands, each bearing an aliphatic octyl chain with a different terminal binding group: C8H17-X, where X = PO(OH)2 (OPA), SO2ONa (OSA), Si(OCH3)3 (OTMOS), and CO2H (OCA). Trialkoxysilanes are widely used surface modifiers for silicate, indium tin oxide, and other metal oxide surfaces. Phosphonic acids have been reported to modify TiO2, ZrO2, and indium tin oxide surfaces and are thought to couple to the surface of metal oxides either by heterocondensation with surface hydroxyl groups or coordination to metal ions on the surface. Carboxylic acid and sulfonic acid groups may also bind to the surface in a similar manner. A sample of each ligand was mixed with BT nanoparticles (30–50 nm, 0.5 mmol ligand/ g BT) in an ethanol/water solution and stirred at 80 °C, followed by extensive washing with ethanol or water and centrifugation to remove excess and/or physisorbed ligand. The treated BT nanoparticles were dried and characterized by using Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). Figure 1a shows a comparison of FTIR spectra in the C–H stretching region for the BT nanoparticles treated with the ligands described above, followed by washing. These results C O M M U N IC A IO N
588 citations
TL;DR: Large-aspect-ratio composite nanofibers with interior hierarchical interfaces are employed to break the adverse coupling of electric displacement and breakdown strength in flexible poly(vinylidene fluoride-hexafluoropropylene) nanocomposite films, which gives rise to the highest energy density ever achieved in polymer Nanocomposites dielectrics.
Abstract: Large-aspect-ratio composite nanofibers with interior hierarchical interfaces are employed to break the adverse coupling of electric displacement and breakdown strength in flexible poly(vinylidene fluoride-hexafluoropropylene) nanocomposite films, a small loading of 3 vol% BaTiO3@TiO2 nanofibers gives rise to the highestenergy density (≈31.2 J cm(-3)) ever achieved in polymer nanocomposites dielectrics.
519 citations