Barium titanate/poly (vinylidene fluoride) nanocomposites with core–shell structure with high dielectric constant and temperature stability prepared via a cold sintering process

Abstract

In this study, a cold sintering process was used to prepare core–shell-structured barium titanate (BT)-based poly (vinylidene fluoride) (PVDF) nanocomposites with high performance. The surface of BT nanoparticles was covered with BT homogeneous sol (defined as BT@HGS). The dielectric constant of the BT@HGS/PVDF nanocomposites increased from 25.4 to 110.9, with the BT@HGS nanofillers increasing from 10 to 50 vol% at 1 kHz. BT@HGS nanoparticles with core–shell structures enhanced interface polarization, improved dielectric properties, and prevented ion conduction inside the composites, which reduced the loss of conductivity and inhibited dielectric loss. BT@HGS/PVDF nanocomposites additionally show excellent temperature stability at 25–150 °C, which is suitable for flexible electronics applications. The BT@HGS/PVDF nanocomposites with high dielectric constant and low dielectric loss demonstrate that the cold sintering process is a promising processing route for designing new high-performance nanocomposites.