<p>This study aims to enhance the piezoelectric performance of lead-free poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanocomposites by incorporating copper-doped barium titanate (CBT) nanoparticles. Composite films were fabricated via the electrospinning technique using varying concentrations of CBT (1–5 wt%). The influence of CBT doping on the polar phase content, morphology, dielectric behavior, and piezoelectric response was systematically investigated. Structural analyses using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy confirmed an increase in polar phase content with higher CBT loading. Field emission scanning electron microscopy (FESEM) images revealed a uniform fiber morphology and reduced diameters with increasing filler content. Thermogravimetric analysis revealed improved thermal stability, while mechanical testing demonstrated enhanced tensile strength, particularly at a 4 wt% CBT concentration. Dielectric measurements revealed higher dielectric constant and loss values as the CBT content increased. In this context, the present work aims to advance the state of the art by combining electrospun PVDF-HFP nanofibers with Cu-doped BaTiO₃ (CBT) nanoparticles as a lead-free piezoelectric filler. Electrospinning is employed to obtain highly flexible, porous fibrous mats with enhanced surface area and alignment of dipoles, which are beneficial for mechanical compliance and charge generation. By optimizing the CBT content, we demonstrate a substantial increase in the polar phase fraction (up to 71.7%) and overall crystallinity (up to 87.8%), as well as improved thermal stability, dielectric permittivity, and mechanical properties. These microstructural enhancements translate into a significant rise in output voltage (up to 2.3&#xa0;V at 5 wt% CBT) and power density, achieved at relatively low filler loadings and without compromising flexibility, thus improving upon previously reported BaTiO₃-filled PVDF-based nanogenerators.</p>