Core-shell structured BaTiO3@SiO2 nanofibers for poly(vinylidene fluoride) nanocomposites with high discharged energy

•Discharged energy density of BT@SiO2 NF/PVDF nanocomposite was investigated.•The properties enhancement mechanism of nanocomposite was proposed.•The efficiency of the nanocomposite films is 62.7% at 3500 kV/cm.

Nanocomposite based on poly(vinylidene fluoride) (PVDF) polymer filled with surface functionalized core-shell structure BaTiO3@SiO2 nanofibers (BT@SiO2 NF) were prepared via the solution casting method. The effect of BT@SiO2 NF filler introduction on the discharged energy density performance of the nanocomposite were investigated. The results indicated that the discharged energy density of nanocomposites is enhanced and the maximum discharged energy density in the nanocomposite with 2.5 vol% BT@SiO2 NF is 6.6 J/cm3 at 3500 kV/cm with an efficiency of above 62.7%. The reason of the enhancement of the discharged energy density performance is that coating SiO2 layers on the surface of BT NF reduces the Maxwell-Wagner-Sillars interfacial polarization. This work may provide a novel route to enhance discharged energy density performance using core-shell nanofibers in polymer-based nanocomposites.