Enhanced flexible piezoelectric energy harvesters based on BaZrTiO3-BaCaTiO3 nanoparticles/PVDF composite films with Cu floating electrodes

Flexible piezoelectric energy harvesters (FPEHs) were fabricated by employing different types of composite materials based on lead-free piezoelectric nanoparticles (LPNPs) and polyvinylidene fluoride (PVDF) with floating electrodes. The floating electrode effects were analyzed through an experiment and simulation. Different types of LPNPs (BaTiO3, Ba(Zr0.04Ti0.96)O-3 (BZT), 1-mol% Cu-doped BZT, Ba(Zr0.2Ti0.8) O-3-50(Ba0.7Ca0.3)TiO3 (BZT-BCT), and 1-mol% Cu-doped BZT-BCT)/PVDF composite films were evaluated for FPEH applications. The FPEH based on the BZT-BCT nanoparticles (NPs)/PVDF composite film with floating electrode exhibited a high performance. The highest energy density (2.79 mJ/cm(3)) was obtained for the FPEH based on the BZT-BCT NPs/PVDF composite film with floating electrode. The results suggest that upon the introduction of the floating electrodes (Cu) into the BZT-BCT NPs/PVDF composite film, charges could be more easily attracted to the floating electrodes that facilitated the collection of charge into the electrodes. (C) 2019 Published by Elsevier B.V.