Enhancing Output and Stability of Droplet‐Based Triboelectric Nanogenerator via Surface Wettability Regulation

With the rapid development of droplet‐based triboelectric nanogenerators (D‐TENGs) for harvesting raindrop kinetic energy, challenges such as electrode corrosion and insufficient output stability persist. To overcome these limitations, this study proposes a surface wettability control strategy. By combining etching with fluorination, a superhydrophobic micro–nano structure was constructed on an aluminum electrode, resulting in a high‐performance and corrosion‐resistant superhydrophobic single‐electrode D‐TENG (SSED‐TENG). The superhydrophobic interface effectively optimizes droplet contact‐separation dynamics and enhances charge transfer efficiency. At a droplet release height of 30 cm, the device delivers an optimal output, with a short‐circuit current of 4.38 mA and an open‐circuit voltage of 425 V. The SSED‐TENG demonstrates efficient energy harvesting, capable of charging capacitors and powering over a hundred light‐emitting diodes. Moreover, the hydrophobic layer provides remarkable corrosion resistance, maintaining stable performance even under simulated acid‐rain conditions. This work offers an effective surface‐engineering approach for developing durable and efficient droplet‐based energy harvesters for practical outdoor applications.