Robust and Flexible Piezoelectric Lead-Free Zn-BCZT/PVDF-HFP Nanogenerators for Wearable Energy Harvesting

Abstract

Herein, flexible piezoelectric nanogenerators were fabricated based on polymer composites containing synthesized lead-free piezoceramics Ba 0.85 Ca 0.15 Zr 0.10 Ti 0.90 O 3 (BCZT) and zincdoped BCZT (Zn-BCZT). Polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP)-based composites were prepared through the solution casting method. The morphology and microstructure were investigated using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The distributions of crystallinity and β-phase fractions were also studied. Impedance measurements illustrate the accumulation of space charge in the high-frequency range and the existence of a non-Debye relaxation. The results show that a 10 wt % Zn-BCZT/PVDF-HFP nanogenerator can generate a maximum peak-to-peak output voltage of 3.3 V and a power of 2.13 μW for a load resistance of 1 MΩ under mechanical shaking. This nanogenerator can successfully harvest a good output voltage of up to 8 V under daily life movements such as walking. This study demonstrates the importance of doping zinc within BCZT to boost the piezoelectric performance as it contributes to minimize the crystallite particle size and enhance the crystal β-phase transformation of the polymer matrix. Hence, the 10 wt % Zn-BCZT/PVDF-HFP nanogenerator has great potential for use in wearable technologies. Furthermore, the nanogenerator demonstrates good stability over 1800 cycles of repetitive load and good reliability even after 1 year. These results indicate the robustness of the developed nanogenerator in practical applications.

Modulating Energy Harvesting Behavior of PVDF Piezo-Polymer by Incorporation of BCZT Ceramic Filler

“…Amina Ben Ayed et al developed a piezoelectric generator constructed from Zn-doped BCZT and a PVDF-HFP composite using the solution casting method. The composite film yielded an output voltage of 3.3 V and a power output of 2.13 μW when tested with a 1 MΩ load resistance, under mechanical shaking . Mingyang Yan et al developed a flexible piezoelectric nanogenerator from Ag-decorated BCZT NWs/PVDF-TrFE tape casting composite film and achieved an output voltage and power density of 3.5 V and 4.5 mW/m 2 respectively .…”

Chemical-Composition Tuning-Enabled Optimization of Structure, Properties, and Performance of Lead-Free (1 – x)BaZr0.05Ti0.95O3–(x)Ba0.92Ca0.08TiO3 Electroceramics

“…Before the RoHS regulation, the well-known PbZr 0.48 Ti 0.52 O 3 , abbreviated as PZT, was a popular material that was used in most of the electronic devices. , The PZT has superior piezoelectric properties among all other Pb-based as well as Pb-free piezoelectric materials. However, due to these regulations, the traditional PZT material is currently disqualified for utilization, as it is dangerous for all living organisms including humans. , Similarly, the Pb-based compounds can get easily mixed with the drinking water sources that can affect the biodiversity of plants and animals. , Thus, the design and development of nontoxic, Pb-free materials, which can replace the traditional Pb-based materials, is highly desirable. − On the other hand, scientifically and technologically, it is a challenging task, which urges the scientific and engineering community to direct attention with rigorous research and development activities. − …”

Piezoelectric and Triboelectric Contributions by Aromatic Hyperbranched Polyesters of Second-Generation/PVDF Nanofiber-Based Nanogenerators for Energy Harvesting and Wearable Electronics

“…In recent years, energy-harvesting nanogenerators (NGs) from human activities have garnered a lot of interest as a potential alternative to energy generated from conventional fossil fuels. − The rapid development in wearable devices that are both stretchable and flexible has been the focus of many research groups around the world. − In our surrounding nature, among the many energy sources that are readily available, mechanical energy is the major one that is also renewable and is transferable into electrical stimuli with the use of different technologies like electrostatic, triboelectric, piezoelectric, and electromagnetic NGs. − Among these, triboelectric NGs (TENGs) and piezoelectric NGs (PENGs) are considered promising strategies to obtain sustainable and efficient mechanical energy.…”