Constant Direct Current Triboelectric Nanogenerator Based on Soft-Contact Mode for Self-Powered Cathodic Protection

Triboelectric nanogenerator (TENG) has been proved to be a promising technology for harvesting decentralized energy. However, the application fields of the traditional TENGs are limited by the high crest factor. Here a constant direct current TENG (CDC-TENG) based on specific phase difference (Δθ) design is proposed. The simple Δθ design avoids the extremely complex angle between the triboelectric layers and greatly reduces the number of rectifier circuits, which decreases the complexity and power loss of the system. The novel 3D encapsulated design ensures the long-term and stable working of CDC-TENG in humid environment. Experiments show that the crest factor significantly decreases with the increase of the number of phases and electrode pairs. The crest factor surprisingly reduces from 1.31 to 1.05. Meanwhile, the current density up to 3021 μA·m−2 is 6.93 % higher than that without the Δθ. Finally, this paper creatively takes the CDC-TENG with constant DC as the power source of cathodic protection (CP) system for the first time, which exhibits better corrosion protection effect than that without Δθ due to the low crest factor. In general, this work provides a meaningful template for TENGs to broaden the marine industrial applications of constant DC demand.