Achieving High Power Density and Durability of Multilayered Swing‐Structured Triboelectric Nanogenerator toward Marine Environmental Protection

Abstract Protecting marine environment is an important and urgent task to maintain marine ecological balance. As a promising blue energy harvesting technology, triboelectric nanogenerator (TENG) can provide electrical energy for marine environmental protection. Previous reported swing‐structured TENGs have advantages of low driving force in low‐frequency water waves and strong durability, but the space utilization and volume power density are relatively low. Here, a multilayered swing‐structured TENG (MS‐TENG) with low wear is designed to increase the space utilization rate, and thereby enhance the output performance. The MS‐TENG generates the highest peak power density of 15.18 W m −3 Hz −1 and average power density of 3.56 W m −3 Hz −1 under water wave triggering at 0.8 Hz. By coupling the charge pumping and non‐contact mode of main TENGs, the MS‐TENG achieves strong performance stability, exhibiting little attenuation of electric output after 240 000 cycles. Furthermore, the MS‐TENG has successfully powered a water quality detector for self‐powered ballast water quality monitoring, and an application is presented about electrical dehydration of water‐in‐oil emulsions driven by the MS‐TENG with a dehydration rate of 99.6%. This work promotes the development of high power density MS‐TENG and demonstrates its application potential for self‐powered marine environmental protection.