Abstract
Piezoelectric nanogenerators (PENGs) that can harvest mechanical energy from ambient environment have broad prospects for multi-functional applications. Here, multi-layered piezoelectric composites with a porous structure based on highly oriented PZT/PVDF electrospinning fibers are prepared via a laminating method to construct high-performance PENGs. PZT particles as piezoelectric reinforcing phases are embedded in PVDF fibers and facilitate the formation of polar β phase in PVDF. The multi-layered, porous structure effectively promotes the overall polarization and surface bound charge density, resulting in highly efficient electromechanical conversion. The PENG based on 10 wt.% PZT/PVDF composite fibers with a 220 µm film thickness output an optimal voltage of 62.0 V and a power of 136.9 μW, which is 3.4 and 6.5 times the voltage and power of 10wt.% PZT/PVDF casting film-based PENG, respectively. Importantly, the PENG shows a high sensitivity of 12.4 VN-1, presenting a significant advantage in comparison to PENGs with other porous structures. In addition, the composites show excellent flexibility with a Young’s modulus of 227.2 MPa and an elongation of 262.3%. This work shows great potential application of piezoelectric fiber composites in flexible energy harvesting devices.
Flexible ultrasonic transducers using piezoelectric fiber composites with antisymmetric interdigital electrodes