High-Output Single-Electrode Droplet Triboelectric Nanogenerator Based on Asymmetrical Distribution Electrostatic Induction Enhancement

Droplet-based triboelectric nanogenerators (D-TENGs) have recently gained much attention due to their great potential in harvesting energy. However, the output performance of conventional single-electrode droplet-based TENGs is limited owing to low induced electrification efficiency. The asymmetric distribution of electric fields on both sides of the electrode edge enhances the electrostatic induction process and improves the output performance of D-TENG. Herein, an induced electrification-enhanced droplet-based triboelectric nanogenerator (IED-TENG) is developed to effectively enhance the output performance by simultaneously optimizing the electrode structure and the dynamics of the water droplet. One droplet falling from a height of 30 cm results in a -70 V output voltage and -6 µA short-circuit current, which is 70 times and 20 times the full-inductive-electrode mode, respectively. The working principle and the relationship between electric signal and droplet dynamics are analyzed in detail. Moreover, the peak output voltage can reach -110 V, and the peak current can get -140 µA by using the power generation of multiple water droplets. The present protocol provides an easy and reproducibility strategy in energy harvesting and sensing areas.

Fluorinated Graphene-Enabled Durable Triboelectric Coating for Water Energy Harvesting

The durability issue of triboelectric nanogenerators (TENGs) still limits its practical application for long-term operation, especially in harvesting water energy, which is one of the most widespread energies in nature. Attempting to ameliorate this, fluorinated graphene (FG) with unique triboelectric negativity and superhydrophobic property is introduced to serve as a new triboelectric and protective layer for TENG construction. The self-cleaning as well as anti-corrosion property and durability of the FG coating-enabled TENG device is then demonstrated. Furthermore, this novel triboelectronegative material candidate is applied for consecutively coating on Cu mesh and the inner wall of sewage pipe to fabricate TENGs for water energy harvesting and working as a metal protective layer in the meantime. Through the extraordinary output performance, the feasibility of FG-enabled triboelectric coating to be used in the field of interference screening, filtering, and sewage pipes is proved. This developed triboelectronegative coating not only broadens the material selection of TENG but also significantly enhances the durability and robustness of TENG for water energy harvesting, which possesses great potential in applying in metal protection and water energy harvesting under extreme conditions (e.g., strong acid and strong alkaline environments).