Nanocomposites of Surface-Modified BaTiO_3 Nanoparticles Filled Ferroelectric Polymer with Enhanced Energy Density

摘要

We report nanocomposites of increased dielectric permittivity, enhanced electric breakdown strength and high-energy density based on surface-modified BaTiO_3 (BT) nanoparticles filled poly(vinylidene fluoride) polymer. Polyvinylprrolidone (PVP) is used as the surface modification agent and homogeneous nano-composite films have been prepared by solution casting processing. The dielectric permittivity of the nanocomposite with treated BT is higher than those with untreated BT and reaches the maximum value of 77 (1 kHz) at BT concentration of 55 vol%. The electric breakdown strength of the nanocomposite is greatly enhanced to 336 MV/m at BT concentration of 10 vol% and the calculated energy density is 6.8 J/cm~3. The results indicate that using PVP as surface modification agent can greatly enhance the dielectric permittivity and electric breakdown strength of the ceramic-polymer nanocomposite and achieve high-energy density for energy storage and power capacitor applications.