Enhanced dielectric performance and energy storage of PVDF‐HFP‐based composites induced by surface charged Al₂O₃

Abstract

In order to enhance dielectric properties and energy storage density of poly(vinylidene fluoride‐hexafluoro propylene) (PVDF‐HFP), surface charged gas‐phase Al2O3 nanoparticles (GP‐Al2O3, with positive surface charges, ε’ ≈ 10) are selected as fillers to fabricate PVDF‐HFP‐based composites via simple physical blending and hot‐molding techniques. The results show that GP‐Al2O3 are dispersed homogeneously in the PVDF‐HFP matrix and the existence of nanoscale interface layer (matrix‐filler) is investigated by SAXS. The dielectric constant of the composites filled with 10 wt % GP‐Al2O3 is 100.5 at 1 Hz, which is 5.6 times higher than that of pure PVDF‐HFP. The maximum energy storage density of the composite is 4.06 J cm−3 at an electrical field of 900 kV mm−1 with GP‐Al2O3 content of 1 wt %. Experimental results show that GP‐Al2O3 could induce uniform fillers’ distribution and increase the concentration of electroactive β‐phase as well as enhance interfacial polarization in the matrix, which resulted in enhancements of dielectric constant and energy storage density of the PVDF‐HFP composites. This work demonstrates that surface charged inorganic‐oxide nanoparticles exhibit promising potential in fabricating ferroelectric polymer composites with relatively high dielectric constant and energy storage. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019, 57, 574–583

Enhanced energy storage of polyvinylidene fluoride‐based nanocomposites induced by high aspect ratio titania nanosheets

“…Comparison of previous published data and our work (1#, 42 2#, 43 3#, 43 4#, 18 5#, 44 6#, 45 7#, 22 8#, 46 and 9# 40 ). PVDF, polyvinylidene fluoride; TNSs, titania nanosheets [Color figure can be viewed at wileyonlinelibrary.com]…”

“…Meanwhile, the unique 2D structure of TNSs plays an important role in enhancement of breakdown strength. According to the F I G U R E 9 Comparison of previous published data and our work (1#, 42 2#, 43 3#, 43 4#, 18 5#, 44 6#, 45 7#, 22 8#, 46 and 9# 40 ). PVDF, polyvinylidene fluoride; TNSs, titania nanosheets [Color figure can be viewed at wileyonlinelibrary.com] previously reported literatures, the TNSs can act as charge barriers under electric field, 39,40 which prevents the formation of electric conductive paths in the nanocomposites.…”

Adjusting the energy gap and interface effect of titania nanosheets synergistically enhances the energy storage performance of PVDF-based composites

“…Compared with the LTNSs, the STNSs possess largely increased ultimately exposed active sites and hydroxyl groups, which could induce more β phase transition. 31…”

Research Progress on Multilayer‐Structured Polymer‐Based Dielectric Nanocomposites for Energy Storage

“…It can be obtained as $${U_{\rm{s}}} = \smallint E{\rm{d}}D$$, which can be determined by the electric displacement (D) and the applied electric field (E). [ 13–18 ] For ideal linear dielectrics, the energy loss due to leakage conduction is assumed to be zero in the charge and discharge processes because ε r does not vary with E. The U e of linear dielectrics is related to E and ε r , as follows: $${U_{\rm{s}}} = \frac{1}{2}{\varepsilon _{\rm{r}}}{\varepsilon _0}{E^2}$$, where ε 0 = 8.85 × 10 −12 Fm −1 is the vacuum permittivity. For nonlinear dielectrics, there is always an energy loss issue during the charging and discharging processes.…”