Gas-solid two-phase flow triboelectric generator for powder triboelectrification energy collection and road early warning.

With the rapid development of modern industrial processes, electrostatic safety issues caused by powder in production and daily life have attracted people's attention. Since powder is small in size and easily agglomerates, it is difficult to observe or design devices to monitor the electrostatic process generated by powder. Herein, a continuous gas-solid two-phase flow triboelectric nanogenerator (GS-TENG) was developed to harvest triboelectricity from the collision process between the powder-air flow and the solid surface. Compared with the signals under non-continuous airflow, the short-circuit current and output voltage signals generated under continuous airflow impact exhibit an unidirectional direct current peak characteristic. Additionally, in order to analyze the relationship between motion of powder airflow and the triboelectric signals, the two-phase flow more comprehensively, a high-speed camera was used to record motion during the charge generation process. Results showed that 3 mm nylon sphere generated normal alternating current signals upon contact and separation from PTFE, while nylon power with the diameter of about 30 µm produced direct current triboelectric signals owing to the effect of point discharge. At a wind speed of 32 m/s, 5 cm distance, 90° impact angle, the short-circuit current and output voltage can reach the maximum values of 20 µA and 130 V, respectively, which can serve as a power source sufficient to power 63 commercial LEDs. Based on the gas-solid two-phase flow triboelectric nanogenerator, a self-powered road warning lights was designed, indicating application prospects in dusty weather. [Display omitted] • A new single-electrode gas-solid two-phase flow TENG system was constructed. • GS-TENG can form a continuous and uniform powder-air two-phase flow. • The effects of distance and angle on the output performance of GS-TENG were studied. • Powder-air two-phase flow collides with the PTFE film, point discharge phenomena occurs. [ABSTRACT FROM AUTHOR]