Enhancing the Output Performance of Tubular Gas-Liquid Mixing Triboelectric Nanogenerator by Bulk Effect.

Gas-liquid two-phase flow-based triboelectric nanogenerators (GL-TENGs) have gained widespread attention due to their ability to convert the kinetic energy of complex flowing fluids into electrical power, but limitation such as relatively low output power density imposed by interfacial effects severely restrict their output performance. Here, a novel tubular bulk effect gas-liquid mixing triboelectric nanogenerator (TBE-GL-TENG) is designed to significantly enhance the output performance of GL-TENGs. The instantaneous output voltage, output current, and transferred charge of 1530 V, 112 µA, and 0.33 µC are obtained for a TBE-GL-TENG device when used with 1.0 mL of tap water, which are ≈5.3, 9.6, and 3.0 times higher than those of the control group based on conventional interfacial effects, respectively. With an instantaneous power output of 18.67 kW m, 640 LEDs can be directly powered by a TBE-GL-TENG device. The working mechanism of TBE-GL-TENG is systematically elucidated from microscopic simulations to macroscopic experiments, and the key factors for enhancing instantaneous output power are discussed in detail. This proposed tubular bulk effect electricity generator based on gas-liquid mixing flow will open new insight in water energy harvesting and self-powered sensing for multi-phase flow systems.