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. A cylindrical triboelectric nanogenerator enabled by coupling swing‐rotation switching mechanism (SR‐TENG) with potential energy storage/release strategy is proposed to harvest irregular, low‐frequency, and low‐intensity mechanical energy. This coupling strategy makes SR‐TENG switch automatically between the intermittent and continuous rotation mode. Compared with traditional cylindrical pendulum TENG, SR‐TENG has a more controllable output, broadens the working bandwidth significantly, and improves output performance greatly.