Optimizing LDH and PVDF-TrFE Composite Layers for High-Performance Flexible Triboelectric Nanogenerators

Eunhye Hwang; Swathi Ippili; Soon-Gil Yoon

Abstract:

The growing demand for sustainable power in wearable electronics, mobile devices, and self-powered sensors has encouraged research into efficient energy harvesting technologies. Mechanical energy generated from human motion and the surrounding environment represents a promising energy source. Triboelectric nanogenerators (TENGs) have attracted considerable attention due to their high efficiency, scalability, and low cost [1–3]. However, improving material properties to enhance output performance and long-term stability remains a challenge.

In this study, a multilayer TENG was fabricated by sequentially depositing RF-sputtered aluminum-doped zinc oxide (AZO), layered double hydroxide (LDH), and spin-coated poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE). LDH layers were grown via an optimized immersion method to ensure uniform coverage, and PVDF-TrFE solutions with varying concentrations were applied to investigate polymer loading effects.

The AZO/LDH TENG exhibited an output voltage of 164.25 V and a current density of 2.9 µA/cm². The composite layer with the optimal PVDF-TrFE concentration significantly enhanced the output, achieving an output voltage of 641.625 V and a current density of 16.530 µA/cm². This improvement is attributed to increased surface charge density and enhanced dielectric properties of the ferroelectric polymer. Long-term stability tests further confirmed the enhanced performance of PVDF-TrFE-coated devices compared to those with LDH only.

These results highlight the synergistic benefits of combining LDH optimization with PVDF-TrFE loading, presenting a promising strategy for the development of flexible, high-performance energy harvesters for wearable and self-powered sensor applications.

References

[1] Fan, F.-R., Tian, Z.-Q., & Wang, Z. L. (2012). Flexible triboelectric generator. Nano Energy, 1(2), 328–334.

[2] Nguyen, T. M. T., et al. (2018). Enhanced Output Performance of Nanogenerator Based on Composite of PVDF and Zn:Al LDHs. Trans. Electr. Electron. Mater., 19, 403–411.

[3] Park, D., et al. (2021). Performance enhancement of flexible polymer triboelectric generator. Applied Sciences, 11(3), 1284.