Improved Energy Density and Energy Efficiency of Poly(vinylidene difluoride) Nanocomposite Dielectrics Using 0.93Na_0.5Bi_0.5TiO₃-0.07BaTiO₃ Nanofibers

Abstract

In modern electronic and power systems, it is essential to develop advanced dielectric materials with high energy density. One-dimensional ferroelectric ceramic nanofibers were proved to be a feasible strategy for improving the permittivity and energy density of nanocomposites. In this paper, to overcome the high loss issue of Na0.5Bi0.5TiO3 (NBT), a kind of novel nanofibers 0.93Na0.5Bi0.5TiO3-0.07BaTiO3 (NBT-BT) with large aspect ratio are synthesized by the electrospinning method and used as the dielectric fillers in trilayer structured poly­(vinylidene difluoride) (PVDF) nanocomposites for energy storage applications. The finite element analysis is performed to evaluate the electric field distribution in the nanocomposites. The results showed that the trilayer structured nanocomposite loaded with 6 wt % NBT-BT nanofibers in the middle layer achieved the highest discharge energy density of 19.21 J cm–3 at 527 kV mm–1, which is 87.2% higher than that of pure PVDF (10.26 J cm–3 at 420 kV mm–1). Owing to the contribution of the barrier effect and interface polarization between adjacent layers, the energy density of the trilayer structured nanocomposites is significantly higher than that of the single-layer nanocomposites. This work provides a kind of novel one-dimensional ceramic fillers for obviously improving the energy density of polymer-based dielectrics.

Achieving synergistic improvement in dielectric constant and energy storage properties of all-organic liquid crystal molecule/PVDF composites

“…The results show that the 5CB/PVDF composite films maintain superior cycle stability over 10 4 cycles, which is of great importance for the long-term usage of the dielectric capacitors. Furthermore, since the uniform stability of the composite is a significant parameter to assess the performance of dielectric film capacitors, 58 the uniform stability of the 5 wt%-5CB/PVDF composite film is studied via measuring the U d and η of different regions under different electric fields (see Fig. 12(a and b)).…”

Ultrahigh energy storage performance of all-organic dielectrics at high-temperature by tuning the density and location of traps

“…S5 and S6 (ESI†). 42 The characteristic E b of the composite dielectric with the trap density is shown in Fig. 3(c).…”

Significantly Enhanced Breakdown Strength and Energy Density in Nanocomposites by Synergic Modulation of Structural Design and Low-Loading Nanofibers

“…For instance, as one of the most representative commercial capacitor films, the energy density of biaxially oriented polypropylene (BOPP) is usually less than 4 J/cm 3 . − To satisfy the demand for miniaturization and integration of electrical and electronic devices, the development of dielectric capacitors with high discharged energy density ( U d ) is highly desired. It is well known that the U d could be garnered from the integration of the electric displacement–electric field ( D – E ) loops and is calculated by the following equation , U normald = ∫ E d D where E is the applied electric field and D represents the electric displacement. Clearly, the enhancement of breakdown strength ( E b ) plays a critical role in realizing the high U d of dielectric capacitors. , In addition, the relative permittivity (ε r ) is also a major factor affecting the U d , which is associated with the D …”

“…Second, the lower surface areas of nanofibers contribute to reducing the surface energy and thus easy to uniformly disperse in the polymer matrix. Third, 1D nanofibers served as scattering centers could retard the movement of electrons and inhibit the longitudinal growth of the electrical tree, giving rise to the improvement of E b . ,, BiFeO 3 –SrTiO 3 is a good chemical stability material with superior ferroelectric and relatively low dielectric loss. , It has been reported that 0.4BiFeO 3 –0.6SrTiO 3 (BFSTO) exhibits favorable energy density, which provides a possibility for BFSTO nanofibers as inorganic fillers to further improve the energy storage performance of organic–inorganic nanocomposites. , …”