Ultra-stretchable and high performance fibrous TENG with helically structured dual-channel Liquid Metal electrode

Abstract

Fibrous triboelectric nanogenerators (FTENGs) are highly desirable nano-energy harvesting devices due to largely available contact area and convenience in integration, which enables more efficient conversion of randomly disordered low-mass mechanical energy into electrical energy. Unfortunately, the high triboelectric output of existing FTENGs under mechanical deformations is considerably limited due to their inherently low stretchability of conductive or friction materials. Therefore, simplified equivalent models are established by mimicking the core–shell structure of natural silk, which discuss the influence of different structural variables of fibers on the electrical energy output, thus guiding the design of construction as well as enhancing the triboelectric behaviors. Herein, we successfully constructed a dual-structure variable FTENG (DF) (dual-channel electrode, twisting) that combines excellent stretch and electric performance by utilizing an efficient and scalable thermal stretching, twisting, and injection process. The twisting process assigns the FTENG a larger effective contact area to enhance the surface charge density of the friction material, while the dual-channel electrode enable faster charge transfer, resulting in a significant improvement in the triboelectric output performance. The open-circuit voltage (Voc) of the DF is up to 265.8 V/m, far surpassing the non-structure variable, single electrode-structure variable and single twisting-structure variable counterpart FTENGs, providing remarkable durability. Also, a single DF has a strain at break of up to 862.3 %, exhibiting excellent mechanical stretchability. Moreover, multiple DFs can achieve more significant electrical output characteristics. The dual-structure variable design and the facile manufacturing method will bring inspiration for the preparation of high-performance energy production devices.