Electric Field Distribution Simulation Design of BaTiO₃-Filled Hetero-Bilayer Composites for Enhanced Breakdown Strength and Energy Storage Performances

Layer-structured polymer-based composites are attracting significant attention in modern power systems and energy storage devices due to their ability to enhance the energy storage performances. In this article, a design strategy is presented to design the unique BaTiO₃ (BT)-filled polyvinylidene fluoride (PVDF)-low-density polyethylene (LDPE) hetero-bilayer structured composites by simulating the electric field distribution and predicting the breakdown strength through finite element analysis to enhance the energy storage performances of the composites. The results show that the electric field redistribution and interlayer interface barrier effect induced by the hetero-bilayer structure enhance the breakdown strength and energy storage performances of the composites. By modulating the BT content to weaken the interlayer electric field distortion and modulating the thickness ratio between layers to optimize electric field distribution and enhance the interlayer interface barrier effect, its performance is gradually enhanced. The finally designed hetero-bilayer composite PVDF-BT15/LDPE (8/2) has a breakdown strength of 267.6 kV mm⁻¹ and a discharge energy density of 3.07 J cm⁻³, which are 146% and 299% higher than that of the blended composite BT15/PVDF, respectively. This study presents an innovative structural engineering strategy for designing high-performance dielectric materials.