Kong Tae-Hoon, Lee Sang-Seok, Choi Geon-Ju, Park Il-Kyu
Department of Materials Science and Engineering, Seoul National University of Science and Technology, Seoul 01811, Republic of Korea.
ACS Appl Mater Interfaces. 2020 Apr 15;12(15):17824-17832. doi: 10.1021/acsami.0c00708. Epub 2020 Apr 3.
Triboelectric nanogenerators (TENGs) have emerged as a next-generation sustainable power source for Internet of Things technology. Polyvinylidene fluoride (PVDF) nanofibers (NFs) have been investigated widely to enhance the TENG performance by controlling their polarity; however, controlling the surface morphology of the PVDF NFs has rarely been studied. Here, surface-roughened, churros-like PVDF NFs were fabricated by controlling the solvent evaporation kinetics. The solvent evaporation rate was modulated by varying the relative humidity (RH) during the electrospinning process. With increasing RH, the fraction of polar β-phase in the PVDF NFs increased, the specific surface area of the PVDF NFs increased gradually and the surface morphology changed from smooth to rough, finally resulting in a churros-like structure. Therefore, the output performance of the TENG devices was enhanced with increasing RH, because of the combined effects of the enlarged surface area and the increased fraction of the polar phase in the PVDF NFs. The TENG device with the churros-like PVDF NFs showed an output voltage of 234 V, current of 11 μA, and power density up to 1738 μW/cm, giving it the capability to turn on 60 series-connected commercial light-emitting diodes without using an external charge storage circuit.
摩擦纳米发电机（TENGs）已成为物联网技术的下一代可持续电源。聚偏氟乙烯（PVDF）纳米纤维（NFs）已被广泛研究，通过控制其极性来提高TENG的性能；然而，控制PVDF NFs的表面形态的研究却很少。在此，通过控制溶剂蒸发动力学制备了表面粗糙、类似吉事果的PVDF NFs。在静电纺丝过程中，通过改变相对湿度（RH）来调节溶剂蒸发速率。随着RH的增加，PVDF NFs中极性β相的比例增加，PVDF NFs的比表面积逐渐增大，表面形态从光滑变为粗糙，最终形成类似吉事果的结构。因此，由于PVDF NFs表面积增大和极性相比例增加的综合作用，TENG器件的输出性能随着RH的增加而增强。具有类似吉事果结构PVDF NFs的TENG器件输出电压为234 V，电流为11 μA，功率密度高达1738 μW/cm²，使其能够在不使用外部电荷存储电路的情况下点亮60个串联的商用发光二极管。
