A universal method for quantitative analysis of triboelectric nanogenerators

Abstract

Triboelectric nanogenerators (TENGs) are promising materials for harvesting mechanical energy from the environment. Although different structures and modes of TENGs have been designed in recent years, a theoretical model that can comprehensively describe all kinds of TENGs has not been developed yet. Therefore, in this work, a universal edge approximation based equivalent capacitance (EDAEC) method is used to demonstrate charge distributions and the electric field in TENGs, providing quantitative analysis for all modes of TENGs. Analytical models and the quantitative Q–V–x relationship are built for various TENGs, including the contact-separation (CS) mode, contact freestanding-triboelectric-layer (CFT) mode, single-electrode contact (SEC) mode, lateral sliding (LS) mode, sliding freestanding-triboelectric-layer (SFT) mode and single-electrode sliding (SES) mode. Furthermore, simulated results based on the finite element method are obtained to validate the results derived from the analytical models, which are in good agreement. This universal method for all modes of TENGs is a milestone for understanding the working principles of TENGs in-depth, optimizing TENGs' outputs, and revealing the relationships between different modes. This work presents a theoretical basis to guide the further development of TENGs in terms of structural design toward efficient energy harvesting.