Wrinkled PDMS/MXene composites: A pathway to high-efficiency triboelectric nanogenerators

Abstract

The increased demand for sustainable and green energy harvesting technologies has led to significant progress in triboelectric nanogenerators (TENGs) technology. However, conventional TENGs have drawbacks that limit their practical use, such as low power output, poor surface contact, and restricted charge production. The majority of problems come from the triboelectric layers' intrinsic smoothness of the surfaces, which lowers the effective contact area, resulting in poor performance of the TENGs. Surface engineering strategies have been explored to overcome this challenge and enhance charge transfer and TENG performance. In the present work, we present a wrinkled PDMS/MXene composite-based TENG, where the introduction of microstructured wrinkles on the surface effectively enhances contact electrification and TENG performance. The surface engineering of triboelectric layer was achieved using simple sandpaper in the present work. A comparative analysis between wrinkled and non-wrinkled PDMS/MXene composites was conducted, revealing that the wrinkled structure significantly amplifies the triboelectric output. The optimized device, incorporating 6 wt% MXene in PDMS, achieved an impressive open-circuit voltage of ∼790 V and short-circuit current of 140 μA, outperforming its non-wrinkled pure PDMS counterpart by 3.2 and 7 times in voltage and current, respectively. Additionally, a peak power density of 17.10 W/m² was attained at an optimal load resistance of 5 MΩ, demonstrating its capability for efficient energy conversion. Finally, the prepared TENG is used to power LEDs and LED lamps, and it is also investigated for a self-powered weighing machine application.