Enhanced β-Phase and Ferroelectric Properties of the BTO–BHF/PVDF-Based Flexible Nanocomposite Film for Energy Storage Device Application

In this study, a polymer nanocomposite was prepared by incorporating ferroelectric barium titanate (BTO) and ferromagnetic barium hexaferrite (BHF) into a PVDF (polyvinylidene fluoride) matrix. The BTO–BHF nanoparticles were synthesized using a high-energy planetary ball mill, and the composite film was fabricated via the drop-casting method. Structural and phase analyses were performed using XRD and FTIR, while AFM revealed the surface morphology. The 90% PVDF-10% [(0.95) BTO + (0.05) + BHF] sample exhibited a remarkable enhancement in dielectric constant (ε r ∼ 33) at 1 kHz due to plasmonic interactions and increased β-phase content. The optimized sample exhibited superior polarization and enhanced energy storage performance, primarily due to the improved interfacial interactions between the PVDF matrix and the embedded BTO–BHF nanoparticles. As a result, the energy density of the optimized composite was measured to be 1.7 mJ/cm 2, reflecting its substantial capability to store and release electrical energy. This noteworthy energy storage behavior highlights the potential of the composite for use in advanced flexible electronic devices, including wearable sensors and self-powered systems.