A facile method to enhance the flexibility and triboelectric output of PDMS using ionic liquid-coated single-wall carbon nanotubes
A facile method to enhance the flexibility and triboelectric output of PDMS using ionic liquid-coated single-wall carbon nanotubes
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DOI：
10.1016/j.nanoen.2021.106908
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发表时间：
2021-12
期刊：
影响因子：
17.6
通讯作者：
Xiaoyue Zhao;Z. Ounaies
中科院分区：
文献类型：
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作者：
Xiaoyue Zhao;Z. Ounaies
基于摩擦电效应的能量收集装置由于其在低频应用中的巨大潜力，特别是在可穿戴电子产品中，近年来受到了广泛的关注。为了实现这些装置，需要具有相对高的导电性和大的摩擦电输出的柔性材料。在这项研究中，使用嵌入式离子液体（IL）涂覆的单壁碳纳米管（SWCNTs）的PDMS复合材料。IL与SWCNT的比率被调整以实现可穿戴摩擦电纳米发电机所需的材料性质。SWCNT-IL-PDMS（IL：SWCNT= 20：1）复合材料与未改性的PDMS相比表现出相对高的电导率（0.004S/m）和增强的摩擦电输出。具体地，开路电压（Voc）和短路电流（Isc）增加三倍。相对高的电导率使复合材料能够在没有电极的情况下转移电荷，并降低摩擦电纳米发电机的内部阻抗。复合材料的柔韧性也得到了改善，表现为拉伸和压缩弹性模量的降低。此外，本文还提出并讨论了电性能和摩擦电输出变化的机理。具体地，具有IL的复合材料的介电常数和电导率的增加可能是由于SWCNT在聚合物基质中的更好分散，并且摩擦电输出的变化是（1）介电常数和电导率之间的权衡的结果，以及（2）随着IL的添加摩擦电极性的移动。这项研究不仅提供了一种简便的方法，同时提高柔性，导电性和摩擦电输出的聚二甲基硅氧烷（PDMS），但也推广的方法，并铺平了道路，探索新的柔性和导电材料的可穿戴摩擦电纳米发电机。
Energy harvesting devices based on triboelectric effect have gained much attention recently due to their significant potential in low-frequency applications, especially in wearable electronics. To enable these devices, flexible materials with relatively high electrical conductivity and large triboelectric output are needed. In this study, a PDMS composite is fabricated using embedded ionic liquid (IL) coated single-wall carbon nanotubes (SWCNTs). The ratio of IL to SWCNTs is tuned to achieve the desired material properties for wearable triboelectric nanogenerators. The SWCNT-IL-PDMS (IL: SWCNT= 20:1) composite exhibits a relatively high electrical conductivity (0.004 S/m) and an enhanced triboelectric output compared to unmodified PDMS. Specifically, the open-circuit voltage (Voc) and the short-circuit current (Isc) are increased by three folds. The relatively high electrical conductivity enables the composite to transfer charges without electrodes and reduces the internal impedance of triboelectric nanogenerators. The flexibility of the composite is also improved, as demonstrated by the decrease in both the tensile and compressive elastic moduli. In addition, the mechanism behind the change in electrical properties and triboelectric output is proposed and discussed in this paper. Specifically, the increase in the dielectric constant and electrical conductivity of the composites with IL is likely due to the better dispersion of SWCNT in the polymer matrix, and the change in the triboelectric output is a result of (1) the trade-off between dielectric constant and electrical conductivity, and (2) the shifting of triboelectric polarity with the addition of IL. This study not only provides a facile method to simultaneously increase the flexibility, electrical conductivity, and triboelectric output of polydimethylsiloxane (PDMS), but also generalizes the approach and paves the way to explore new flexible and electrically conductive materials for wearable triboelectric nanogenerators.