Enhanced Piezoelectric and Mechanical Performance in Electrospun PVDF-HFP/BCZT Nanofiber Composites for Energy Harvesting

Highly polarized electrospun PVDF-HFP/BCZT nanofiber composite films were successfully fabricated and systematically investigated for their dielectric, ferroelectric, piezoelectric, mechanical, and energy-harvesting performance. The electrospinning fabrication process, along with the incorporation of Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZT) nanoparticles, significantly enhanced β-phase content along with the interfacial polarization within the polymer matrix. Optimal performance was achieved at 30 wt % ceramic loading. The optimized composite exhibited a high dielectric constant, improved remnant polarization, low leakage current density (∼10−6 A/cm2 at 350 kV/cm), and superior energy storage performance, with a recoverable energy density of 26.41 mJ/cm3 and an efficiency of 52.47%. Nanoindentation analysis revealed enhanced mechanical stability, with an elastic modulus of 9.26 ± 0.2 GPa, enabling efficient mechanical stress transfer for piezoelectric applications. Piezo-response force microscopy confirmed enhanced electromechanical coupling, with the effective piezoelectric coefficient (d33*) improving from ∼38.3 to ∼161 pm/V. The piezoelectric energy harvester based on the optimized nanofiber film delivered an output voltage of 68.4 V and a power density of 406.4 μW/cm3 under cyclic loading, demonstrating excellent durability and real-world applicability. These results establish PVDF-HFP/BCZT nanofiber composites as promising candidates for flexible, self-powered energy-harvesting and sensing systems.