A strategy to develop highly efficient TENGs through the dielectric constant, internal resistance optimization, and surface modification

Abstract

Triboelectric nanogenerators (TENGs) represent a comprehensive achievement in green and eco-friendly technology by transforming ambient mechanical energy into electrical energy. Enhancement of the tribo-charge density on the active layer of TENGs has become a fundamental method of augmenting the output performance of TENGs in realistic environments to increase their use in daily applications. Herein, an approach of coupling piezoelectric/ferroelectric properties, internal resistance, and surface texture of the composite film is established to optimize the output performance of poly-dimethylsiloxane (PDMS)/zinc stannate (ZnSnO₃)/multi-walled carbon nanotube (MWCNT) composite based TENGs. The effect of piezoelectricity, internal resistance, and surface treatment on output is explained experimentally and theoretically, which illustrates that the extent of charge transfer has a strong connection with the piezoelectricity, internal resistance, and surface treatment of the composite. With optimization of these controlling factors, under human finger tapping the fabricated TENG exhibited an open circuit voltage of ∼475 V, a short-circuit current of ∼36 μA, and a charge density of ∼0.062 mC cm⁻², which gives a maximum power of ∼4.2 mW at ∼50 MΩ resistance. Moreover, the designed TENG is able to harvest electrical energy efficiently from various human movements with an energy conversion efficiency of ∼68%, and the output power of the TENG can be used directly or after storage in a capacitor. Thus, this work will deliver not only a new, effective and feasible approach to improve the generated output power from nanogenerators, but also deliver a new opening for constructing high performance TENGs for self-powered day-to-day use electronics.