Surface‐Confined Winding Assembly of SiO2 on the Surface of BaTiO3 Leading to Enhanced Performance of Dielectric Nanocomposites

Abstract

AbstractIn response to the demand for miniaturization and lightweighting in the electronics industry, achieving enhanced energy density of dielectrics is crucial. Constructing nanocomposites consist of ceramic fillers and polymer matrix is an effective strategy in this regard. To address the adverse coupling between polarization and breakdown strength of the nanocomposites, a series of BaTiO3@SiO2 nanofillers with customizable SiO2 shell coverage degrees (90°, 180°, and 360°) is designed and synthesized by surface‐confined winding assembly of SiO2 on the surface of BaTiO3. When a half area of BaTiO3 core is coated by SiO2 layer, it is defined as 180°. A larger coverage degree implies better reduction of leakage current injection, and more effective suppression of local electric field concentration. However, it also leads to a more pronounced reduction in the polarization. 180° BaTiO3@SiO2 demonstrates the most effective mitigation of the adverse coupling between polarization and breakdown strength in nanocomposites. The 180° BaTiO3@SiO2/Poly(vinylidene fluoride) (PVDF) nanocomposite achieves high breakdown strength while maintaining relatively higher polarization intensity, for example, the energy density reaches 20.64 J cm−3 at 650 MV m−1, which is 2.62 times of pure PVDF. This work reveals the growth mechanism of customizable SiO2 shell coverage degrees on BaTiO3 surfaces, providing an effective strategy for high‐performance dielectrics