Design, preparation and application of high-performance PVDF-based piezoelectric nanogenerators

• The performance optimization strategies for PVDF based PENG are roundly reviewed. • Diverse application fields of PVDF based PENG are presented to promote its versatile utilization. • A systematic theoretical framework is provided to underpin the future development of PVDF based PENG. Nowadays, there is a growing potential for miniaturized, wearable and portable electronic devices. Whilst the environmental impact of fossil fuel consumption and the limited lifespan of batteries have redirected of focus of energy research towards the integration of green renewable technologies. Therefore, piezoelectric nanogenerators (PENG) have attracted extensive attention to develop a more efficient and lightweight power source, which possess excellent mechanical properties, good environmental adaptability and excellent energy harvesting performance. As a crucial foundation, polyvinylidene fluoride (PVDF) and its copolymers are the most promising piezoelectric materials for design of PENG due to their unique electrical activity, high flexibility, good processability and long-term stability. However, the piezoelectric response generated by PVDF-based piezoelectric nanogenerators is still low and cannot drive most electronic devices. Consequently, this paper reviews the recent progress in optimizing the output performance of PVDF-based PENG through incorporation of nano-fillers, improved structure design and preparation techniques. The specific applications, current challenges and future prospects in various fields of energy harvesting are also outlined and discussed. This review will help researchers to understand the piezoelectric properties of PVDF-based PENG more systematically, and achieve new research breakthroughs in this field.