Enhanced dielectric properties of BaTiO3/poly(vinylidene fluoride) nanocomposites for energy storage applications

Abstract

In this work, homogeneous ceramics-polymer nanocomposites consisting of surface treated BaTiO3 (BT) particles as fillers and poly(vinylidene fluoride) polymer as matrix have been prepared using a solution casting process. The nanocomposites exhibit enhanced dielectric permittivity and reduced loss tangent. The frequency and temperature dependencies of the dielectric permittivity and loss tangent of the nanocomposites suggest that the introduced BT phase and interface areas contribute to the improvement of the dielectric responses. Meanwhile, the X-ray diffraction patterns and Differential Scanning Calorimetry (DSC) curves indicate that the incorporation of ceramic particles contributes to the decrease of the crystallite size, the increase of the crystallinity, and the shift of the crystallization temperature of the polymer matrix. Furthermore, the dielectric displacement and energy density of the nanocomposites are significantly enhanced and an energy density of 3.54 J/cm3 was obtained under an electric field of 200 MV/m with the BT concentration of 20 vol. %. The results indicate that the introduced ceramic fillers and interface areas have positive influences on the structure of the polymer matrix and contribute to the enhancement of the dielectric responses and energy storage properties of the nanocomposites.