Corrugated Wind-driven Triboelectric Nanogenerator With High Current Density

Due to the rapid development of the Internet of Things（Io T）,wireless sensor nodes become ubiquitous network tentacles,providing reliable ways for people to obtain any required information.It is urgent to develop green,clean and sustainable energy for powering portable electronic devices to meet the continuous and effective power supply for these sensor nodes.Triboelectric nanogenerator（TENG）is a new type of power generation device,which has advantages of small size,low cost,simple fabrication,and easy portability.Wind energy is one of the most widely existing renewable energy in nature.Wind-driven TENG is a new way for power supply due to its capability for wind energy collection.Although researchers have made a lot of studies in wind-driven TENG,the wind-driven TENG still has a relatively low output performance,restraining its applications.In this paper,a wind-driven TENG with corrugated structure is designed and fabricated to enhance airflow disturbance.This corrugated structure can effectively increase the disturbance effect of the device on airflow and improve the vibration intensity of the friction layer,leading to the improvement of the output performance of the TENG.It is proved that the corrugated structure has a greater disturbance on airflow by software COMSOL.The wind speed,vorticity and pressure gradient have a rapid great change when the airflow passes through the partial area of the corrugated structure,leading to the increase of the vibration frequency and amplitude of the thin film.This indicates that the output of the TENG can be improved by introducing corrugated structure.The performance of corrugated structure TENG is greatly improved compared with the planar TENG prepared with the same material.The short-circuit current of the corrugated structure TENG is 43μA when driven by 10 m/s of wind speed,which is 6.14 times of the planar device.The TENG with corrugated structure can work normally in the range of 5 m/s to 15 m/s of wind speed,in which the maximum short-circuit current reaches 131μA.At the same time,the output performance of corrugated structure TENG is not affected by the wind angle in the range of 10°to 50°,which is conducive to flexible application in practical environments.This corrugated structure TENG can both collect wind energy as well as raindrop energy.In order to further improve the output of the device,we designed the lower friction layer in a corrugated structure,and fabricated a double-layer corrugated structure TENG,which improved the contact efficiency and space utilization of the two friction layers.Under the same test conditions,the short-circuit current of the double-layer corrugated structure TENG is 2.14 times of the single-layer corrugated structure TENG,and the amount of transferred charge per unit time is 3.02 times of the single-layer corrugated structure TENG.The obtained optimal corrugation period length,corrugation height and friction layers spacing is 21 mm,6 mm and 2 mm,respectively,after optimizing the structural parameters of the double-layer corrugated structure TENG.Under the 18 m/s of wind speed,the short-circuit current of the device can reach410μA,and the areal current density can reach 17.08μA/cm~2,which is 1.17 times of the highest current density reported in the literature on wind-driven TENG.