Lead-free Ba0.85Ca0.15Zr0.1Ti0.9O3 piezoelectric nanofiber was synthesized using the electrospinning technique. The surface of sintered BCZT nanofibers was modified by dopamine via the chemical coating method. Dopamine-modified BCZT nanofibers were used as fillers in polyvinylidenefluoride-hexafluoropropylene (PVDF-HFP) polymer matrix to cast flexible composite films by solution casting method. Nanofibers and composite films were analyzed by XRD and FE-SEM to investigate crystal structure and morphology, respectively. The broadband dielectric spectroscopy was carried out in composite films having 3.4-24.1 vol% BCZT nanofibers. The composite film having 24.1 vol% nanofibers showed a maximum dielectric constant (61 at 1 kHz) compared with other films. A flexible nanogenerator (NG) was fabricated using epoxy as a packing material. The developed NG tested in different tapping modes and exhibited maximum output voltage and power density around 10 V and 2.9 mu W/cm(3), respectively.