Significantly Enhanced Dielectric Performance of Poly(vinylidene fluoride-co-hexafluoropylene)-based Composites Filled with Hierarchical Flower-like TiO₂ Particles

Abstract

In this study, we report a feasible strategy for fabricating high-dielectric-constant polymer composites for applications in energy storage devices and embedded capacitors. Hierarchical flower-like TiO2 particles were prepared via a facile solvothermal process and incorporated into the P(VDF-HFP) matrix. The temperature and frequency dependent dielectric properties of flower-like TiO2/P(VDF-HFP) composites as well as commercial TiO2/P(VDF-HFP) composites were investigated. The results reveal that the flower-like TiO2 particles are more effective in increasing the dielectric constant of P(VDF-HFP) when compared with commercial TiO2. Typically, the dielectric constant of the P(VDF-HFP) composite filled with 20 vol % flower-like TiO2 reaches 83.1 at 100 Hz, in contrast to 43.4 for the composite filled with 20 vol % commercial TiO2 and 11.3 for pristine P(VDF-HFP). Also, the flower-like TiO2-filled composites exhibit similar characteristic breakdown strengths to their commercial TiO2-filled counterparts. The significant improvement in the dielectric constant could be attributed to the enhancement of Maxwell-Wagner-Sillars polarization, which originates from the sophisticated morphology of flower-like TiO2 particles.

Improved dielectric permittivity and retained low loss in layer-structured films via controlling interfaces

“…However, the dielectric permittivities of polymer dielectrics are usually very low (below 10 @1 kHz), which greatly hindered their wide applications. Toward this end, two strategies have been developed to improve the dielectric constants of polymer composites: (1) ceramic-polymer composites composed of high-k ceramic fillers (e.g., BaTiO 3 [23][24][25][26][27], TiO 2 [28,29], SrTiO 3 [30]) dispersed in polymer matrix and (2) conductor-polymer composites consisting of conductors (e.g., metals, [31,32], graphite [33,34], carbon nanotube [35][36][37], graphene [38,39], carbon black [40], and conductive polymer [41,42]) dispersed in polymer matrix. For ceramic-polymer composites, the enhancement of permittivity is limited (below 50 @10 kHz) even when the ceramic loading excesses 50 vol%, leading to deteriorated mechanical properties, high loss, and low breakdown strength [43].…”

Superior Energy Storage Performances of Polymer Nanocomposites via Modification of Filler/Polymer Interfaces

“…In recent years, various nonconducting nanoparticles with different dimensions have been introduced into polymer matrix. These nanoparticles mainly include high‐ε r ceramic nanoparticles such as BaTiO 3 , TiO 2 , ZrO 2 , (Ba x Sr 1− x )TiO 3 , CaCu 3 Ti 4 O 12 , Pb(Zr x Ti 1− x )O 3 , naturally nanosized silicate minerals (attapulgite, montmorillonite, clay), and other materials with excellent electrical and thermal properties, such as boron nitride …”

Remarkably improved electromechanical actuation of polyurethane enabled by blending with silicone rubber

“…1,4,8,10 To conquer the challenge, many researchers have dedicated to fabricating elastomers with enhanced dielectric permittivity to improve the electrostatic pressure. 8 Various ceramics with high dielectric permittivity, 11,12 conductive nanomaterials, 13,14 and organic strong polar molecules [15][16][17] have been chemically/physically incorporated into the elastomers. Though the actuation of DEAs can be improved in some extent, the increase in elastic modulus and severe deterioration in dielectric strength limit the practical applications of such elastomers.…”