Improving dielectric properties and energy storage performance of poly(vinylidene fluoride) nanocomposite by surface-modified SrTiO3 nanoparticles

Homogeneous nanocomposites flexible films is fabricated by incorporating surface modified paraelectric SrTiO3 nanoparticles (ST NP) by polyvinylpyrrolidone (PVP) into a polyvinylidene fluoride (PVDF) matrix. A systematic study was investigated on the effect of surface modified ST NP fillers on the dielectric properties and energy storage density of the nanocomposite films. Compared to pure PVDF, nanocomposite films with 5 vol % surface modified ST NP show a maximal energy density of 5.1 J/cm3, which is 182% higher than that of the pure PVDF. Moreover, the nanocomposites films exhibits a high efficiency of 80.7% at electric fields below 1000 kV/cm and still higher than 64.6% at an electric field of 2700 kV/cm. The results demonstrate that the nanocomposites films using the surface modified paraelectric fillers exhibit high energy storage densities and high efficiency.