Multi-layered triboelectric nanogenerator incorporated with self-charge excitation for efficient water wave energy harvesting

As one of the promising renewable and clean energy sources, water waves have attracted intensive attention and are expected to convert into electricity to alleviate energy demand. The emergence of triboelectric nanogenerator (TENG) provides a new idea for harvesting and utilizing this low-frequency and random energy, but the low output performance of TENG hinders its widespread application. In this work, an effective strategy that combines multi-layered structure design and external circuit optimization is proposed to efficiently scavenge the water wave energy. Consequently, an average power density up to 27.8 W m- 3 Hz-1 (corresponding output power: 194.5 mu W) has been achieved on the multi-layered TENG. Meanwhile, this strategy also demonstrated that the average power density can be effectively improve to almost 9 times that of the multi-layered TENG without external circuit when triggered by water wave. This work not only provides an efficient strategy for harvesting water wave energy, but also lays a foundation for advancing the practical application of TENG in renewable and clean energy.