A strategy to develop an efficient piezoelectric nanogenerator through ZTO assisted γ-phase nucleation of PVDF in ZTO/PVDF nanocomposite for harvesting bio-mechanical energy and energy storage application

Abstract

Extracting energy from various types of mechanical forces through piezoelectric nanogenerator (PNG) exhibits a great potential for powering up low-power portable devices and self-powered electronic systems. Here, the ferroelectric and lead-free perovskite zinc titanate (ZTO) nanoparticles mitigate to align the molecular –CH2/CF2 dipoles of PVDF, promoting the nucleation of electroactive γ-phase in the PVDF matrix (γ-PVDF), which is responsible for the generation of piezoelectricity of the PNG without any electrical poling treatment. The fabricated PNG with 2 wt% ZTO loading shows a maximum output voltage up to ∼25.7 V and current ∼1.2 μA with a power density of ∼8.22 μW. cm−2 under cyclic finger imparting with a constant pressure (∼16.5 KPa). In addition, the PNG is capable of harvesting energy from a wide variety of easily manageable mechanical stress source such as human body movement, walking, and machine vibration and exhibits high durability for about four weeks without any deterioration in the output performance. Furthermore, the ZTO/PVDF films demonstrate a higher electrical energy density of ≈0.267 J cm−3 at an electric field of 600 kV cm−1, which makes it fit for electrical energy storage device. This high performance ZTO/PVDF hybrid film paves a new and effective way to fabricate eco-friendly devices, active sensors, and flexible nanogenerators for powering small portable electronic appliances and flexible high energy density capacitors as well.