High energy density polymer nanocomposites with Y-doped barium strontium titanate nanoparticles as fillers

Abstract

Dielectric nanocomposites with an enhanced energy density are highly desired in modern electronic and electrical power systems. In this study, the authors developed a new flexible dielectric nanocomposite thin film using Y-doped barium strontium titanate (Y:BST) nanoparticles as fillers and polyvinylidene fluoride as a polymer matrix. The nanocomposites exhibited a high energy density of 11.07 J/cm3 at 4300 kV/cm with a low filler content. Through the analysis of defect chemistry with X-ray photoelectron spectroscopy, the dopant Y3+ occupies A-site of the perovskite structure, which is associated with the generation of Ba&Sr vacancies and oxygen vacancies for charge compensation. As a result, TiO62- octahedron distortion occurs, which is responsible for the enhanced dielectric permittivity. Meanwhile, the dielectric loss maintains a low level and the breakdown strength increases at a low filler loading, resulting in improved energy density.