Study On The Performance Of Triboelectric Nanogenerator Based On Charge Excitation

As an emerging energy harvesting device,the triboelectric nanogenerator(TENG)plays an important role in the fields of micro/nano energy harvesting and self-powered systems.To realize the wide application of TENG,the improvement of its output performance has become one of the core research contents in this field.Since the output power density of TENG is quadratic related to its surface charge density,a lot of research has been devoted to improving its surface charge density.Dielectric material is an important component of TENG and one of the important factors affecting the output performance of TENG.In this thesis,based on charge excitation strategy,the dielectric layer is optimized and explored to achieve the high output performance of TENG.Firstly,based on analysis of the dynamic equilibrium between the accumulation and decay of the surface charge of TENG,the self-charge excitation is used to increase the accumulation speed of the surface charge to improve the equilibrium state of surface charges.Through the optimization of the excitation circuit,the fast accumulation of surface charges and high equilibrium state are realized.It is found that the high relative permittivity of dielectric materials is beneficial to improve the equilibrium state of surface charges and output performance of TENG by optimizing the dielectric materials.The utilization of the materials with high relative permittivity can avoid the use of the ultra-thin dielectric layer which is used in the previous charge excitation research,thereby avoiding the decrease of contact efficiency between the friction layer or the increase of the leakage current.At a working frequency of 2.5 Hz,the maximum power density of the TENG based on the P(VDF-TrFE)film is 40.0 Wm^-2,which can be used to drive multiple LED lights and electronic watch.In addition,the influence of environmental humidity on the output performance of TENG is explored.As the relative humidity increases in the environment,the output performance of the common TENG will drop sharply.However,the use of charge excitation strategy can effectively improve the output performance of TENG in a humidity environment.In a 90%relative humidity environment,the charge density of TENG using both fast charge accumulation and high relative permittivity material can be maintained at 1.30 mC m^-2,which provides an effective method to improve the output performance of TENG in a high humidity environment.Secondly,based on the recyclable material of milk carton,a low-cost,simple preparation,environmentally friendly,and high-output TENG can be prepared,which not only meets the development requirements of environmental protection,but also realizes energy harvesting.Due to the poor electrification performance of the polyethylene film in the milk carton,the output of TENG is merely 0.035 mC m^-2 during stable operation.Since the output performance of TENG based on recyclable materials is limited by triboelectrification,the charge excitation strategy is used to break through the limitation of triboelectrification on the surface charge density,thus improving the output performance of TENG and expanding the range of material selection.Taking advantage of external charge excitation,the surface charge density of TENG based on recyclable materials can be raised to 1.00 mC m^-2,and the maximum power density reaches 14.1 Wm^-2Hz^-1,which can drive electronic devices to work normally.