Durable Roller-Based Swing-Structured Triboelectric Nanogenerator for Water Wave Energy Harvesting.

Ocean energy is a kind of clean and renewable energy source, but it cannot be efficiently harvested by traditional electromagnetic generators, due to its low-frequency characteristic. The emergence of triboelectric nanogenerators provides a more promising technology for collecting ocean energy. In this work, a durable roller-based swing-structured triboelectric nanogenerator (RS-TENG) is designed and fabricated for low-frequency water wave energy harvesting. The rolling structure reduces the wear between triboelectric materials and improves the device's durability. After a continuous operation of 1 260 000 cycles, the attenuation of the electrical outputs of the RS-TENG is below 1.6%, exhibiting excellent durability. At the same time, the output current can arrive at 53.2 µA. Under the triggering of water waves, the RS-TENG can generate an output power of 4.27 mW, corresponding to a power density of 1.16 W m-3. After the arraying, the output performance can be doubled, so that the TENG can successfully power an environmental monitoring sensor and ensure long-term stable operation of the sensor. This work provides an effective strategy for improving the device durability, which benefits the practical applications of the TENGs in large-scale blue energy harvesting.

High-Durability Stacked Disc-Type Rolling Triboelectric Nanogenerators for Environmental Monitoring Around Charging Buoys of Unmanned Ships.

Triboelectric nanogenerator (TENG) as a means of energy harvesting can effectively harvest ocean wave energy, but the energy conversion efficiency and stability of the device during long-term operations are still problems that must be solved for TENGs. Decreasing the frictional resistance between two triboelectric material surfaces is one of the critical approaches for improving the device efficiency and durability. In this work, a novel stacked disc-type rolling triboelectric nanogenerator (SDR-TENG) is designed and fabricated for low-frequency water wave energy harvesting. After 860 000 working cycles, the electrical output attenuation of the SDR-TENG basic unit is less than 5%, showing excellent device durability. Under the simulated water wave conditions, the SDR-TENG with four rolling TENG units can produce an output current of 84.4 µA and an output power of 7.6 mW, corresponding to an effective power density of 16.8 W m-3. This work not only proposes a strategy to effectively enhance the durability of the devices, but also provides a feasible solution for monitoring the surrounding environment of the charging buoys of unmanned ships.