Enhancing output performances and output retention rates of triboelectric nanogenerators via a design of composite inner-layers with coupling effect and self-assembled outer-layers with superhydrophobicity

Abstract

Abstract Low output performances and output retention rates in high humid environments represent serious challenges that have interrupted the large-scale application of triboelectric nanogenerators (TENGs) as portable power supplies and self-powered sensors. Existing approaches of tribo-material optimization and device structure design remain limited in solving the problems of low electrical outputs and output retention rates for TENGs. Here, achieving high electrical outputs and output retention rate in a TENG based on a multi-effect inner-layer and a superhydrophobic outer-layer is first proposed by an organic-inorganic composite and simple self-assembly electrospinning. The inner-layer consisting of polyimide (PI) and 0.85Na0.5Bi0.5TiO3-0.15SrTiO3 (NBT-15ST) ceramic particles (CPs) can distinctly enhance the electrical performances of the device by coupling charge storage effect and hysteretic dielectric polarization. Under a maximum instantaneous force of 50 N, the device delivers a voltage of 1020 V and a current density of 32.5 μA cm−2. Meanwhile, the superhydrophobic outer-layer with novel biomimetic multilevel structures endowing the device with a superior output retention rate of 50% at a high relative humidity of 80%. This work provides a new strategy to optimize the electrical outputs of the TENG and extends its application in humid conditions.