Coating Fluoropolymer on BaTiO₃ Nanoparticles to Boost Permittivity and Energy Density of Polymer Nanocomposites

Abstract

Significantly enhanced dielectric constant and energy storage density positively facilitate miniaturising dielectric capacitors for various applications in electronics and electrical devices. Herein, a fluoropolymer is coated on BaTiO3 (BT) nanoparticles to form a core–shell structure (BT@PF80), which is used as additional dipoles to enhance the dielectric constant and energy density of polymer nanocomposites. Characterizations with various techniques show uniform dispersion of nanoparticles and good compatibility of interfaces in polymer nanocomposites. Furthermore, the dielectric constant increases from 7.85 of neat polymer to 9.43 of the nanocomposites filled with BT@PF80 while the dielectric loss further decreases from 0.05 to 0.04 at 1 KHz. In addition, 7.79 J cm−3 of energy density is achieved at the nanocomposites filled with BT@PF80, which is 2.65 times higher than that of the neat polymer. This work presents a simple and effective means to enhance dielectric constant and energy density, which tends to fertilize the fabrications of polymer dielectrics for electric energy storage.

Optimizing the dielectric constant of the shell layer in core–shell structures for enhanced energy density of polymer nanocomposites

“…However, a fatal factor to the energy density of polymer nanocomposites is local electric field concentration that makes the corresponding regions much more vulnerable to dielectric breakdown. 31–34 Generally, it results from the microstructures of nanoparticles, such as dielectric constant mismatch between the nanoparticles and polymer matrixes. Fortunately, numerical simulation methods have been verified as a feasible means to mitigate local electric field concentration with optimal design of the dielectric constants of the shell layer to couple with those of polymer matrixes and nanoparticles.…”