Enhancing thermal stability of P(VDF-HFP) based nanocomposites with core-shell fillers for energy storage applications

摘要

Improving thermal stability of the ceramic-polymer based nano-composited electrostatic capacitors is the key element to their practical applications in harsh environment. In this paper, Fe3O4 @BaTiO3 particles with thermal conductive core and high-k shell were prepared and used as fillers to improve the thermal stability and high temperature energy storage density of poly-(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) based composited films. Compared to the pure polymer, the films with 10 wt% fillers showed enhanced temperature stability at the range of 40-120 degrees C. The high-temperature (120 degrees C) average breakdown strength reached at 1615 kV/cm with similar to 170% higher than the pure P(VDF-HFP) (970 kV/cm). The discharged energy storage density (120 degrees C) was 1.68 J/cm(3) (1750 kV/cm), which was enhanced up to 1150% comparing to that of pure P (VDF-HFP) (0.146 J/cm(3) at 1300 kV/cm). The increased thermal conductivity and the Internal Barrier Layer Capacitor (IBLC) effects at the conductive-insulating interfaces contribute to the enhanced features. The results in the present work explored an effective way to prepare high temperature dielectric nanocomposites for harsh applications in energy storage field.