Electron structure in modified BaTiO ₃ /poly(vinylidene fluoride) nanocomposite with high dielectric property and energy density

Abstract

It's significantly urgent to develop the polymer film capacitor with large energy density and high charge-discharge efficiency for the applications of portable electronics and power hybrid system. In this study, poly(vinylidene fluoride) (PVDF) nanocomposite film incorporated with tetradecylphosphonic acid modified BaTiO 3 was prepared via solution casting to achieve high dielectric property and large energy density. The strong interactions were formed between modifier and polymer segments, which was characterised by X-ray absorption near edge structure of synchrotron radiation. The decrease of activation energy indicates that the functionalisation of BaTiO 3 weakens the heterogeneous nucleation of nanoparticle. The dielectric constant of 30 vol.% nanocomposite film achieves 50.1 with low loss of 0.02 at 100 Hz, which is attributed to the strong interaction between the phosphonic acid and fluoride atoms of PVDF segments. The energy density of 20 vol.% nanocomposite is 4.4 J/cm 3 with charge-discharge efficiency of 78% at 120 MV/m due to the large interfacial polarisation. The functionalisation strategy of high-k nanofillers enhances the compatibility in polymer nanocomposite, which contributes to the flexible polymer capacitor with large energy density and high charge-discharge efficiency.

Excellent Energy Storage Performance of Ferroconcrete-like All-Organic Linear/Ferroelectric Polymer Films Utilizing Interface Engineering

“…Polymer-based composites possess the disadvantage, however, that use of a ferroelectric ceramic phase with a high dielectric constant always produces higher bulk conductivity in the composites. This results in an abrupt increase in conductive loss of the polymer-based composite and a sharp decrease in efficiency under high electric fields, especially at high filler concentrations. − In addition, the mismatch of the dielectric properties and defects between the filler and the polymer matrix sharply decreases the breakdown strength of the composites. − Therefore, research into all-organic polymers is underway to effectively avoid the disadvantages of composites.…”

Improving Energy Storage Density and Efficiency of Polymer Dielectrics by Adding Trace Biomimetic Lysozyme-Modified Boron Nitride

“…However, the η is rather small, especially at high field; it usually goes down to 40–60%. That means 40–60% energy has been lost during one charging and discharging circle, which is not acceptable for energy storage capacitors application. − …”

Correlating the Interfacial Polar-Phase Structure to the Local Chemistry in Ferroelectric Polymer Nanocomposites by Combined Scanning Probe Microscopy

“…Most of the previous studies trying to understand the interface issue use bulk nanocomposite-based analyzing techniques to indirectly infer the interfacial property and structure [34][35][36][37][38]. For example, based on the result of Fourier-transform infrared spectroscopy (FTIR) and dielectric spectroscopy, it is proposed that the surface interaction of the embedded nanoparticles with the polymer matrix locally promotes the formation of β-phase configuration in the poly(vinylidene fluoride) (PVDF) and its copolymers, and thus significantly impacts the overall dielectric constant of the nanocomposite [17,[39][40][41]. This strategy is somewhat hypothetic, since it is usually challenging to completely distinguish the effect of interface from that of the intrinsic polymer/nanofiller properties under the framework of bulk material measurements, most of which are lack of sufficient spatial resolution.…”