Broadband and Output‐Controllable Triboelectric Nanogenerator Enabled by Coupling Swing‐Rotation Switching Mechanism with Potential Energy Storage/Release Strategy for Low‐Frequency Mechanical Energy Harvesting

Irregular and low-frequency mechanical energy, including ocean energy, is widely distributed but mostly wasted. Triboelectric nanogenerator (TENG) has been proved as a very promising ocean energy harvesting technology. However, the traditional cylindrical pendulum TENG (CP-TENG) can only work effectively in a narrow frequency bandwidth. In this work, a triboelectric nanogenerator enabled by coupling the swing-rotation switching mechanism with a potential energy storage/release strategy (SR-TENG) is presented. It can convert various swing/vibration mechanical energies into electric energy, and it has a controllable output performance whether it works under intermittent rotation mode or continuous rotation mode. This coupling results enable SR-TENG to efficiently harvest low-frequency mechanical energy from 0.3 to 5 Hz. Therefore, its bandwidth is about four times larger than that of CP-TENG. The peak power density of SR-TENG can reach 10.1 W m(-3) at 1.8 Hz and 15.4 W m(-3) at 5 Hz, respectively. Moreover, its durability is improved greatly due to its non-contact working mode. Based on this SR-TENG, several applications toward smart ocean, including a self-powered and wireless hydrological information monitoring system, are demonstrated successfully. These strategies are very helpful to improve the bandwidth, the output performance, and the durability of TENGs.