| With the development of human society and the explosion of science and technology,the constant consumption of fossil energy has led to serious energy crisis and environmental pollution.At present,the global development and utilization of clean energy such as biological energy,hydrogen energy,geothermal energy,water energy,wind energy,solar energy,etc.,is the means to solve this problem.But expensive,complex,cumbersome and inefficient devices designed to capture clean energy make them unsuitable for powering portable electronics and widely distributed sensor networks.Therefore,mobile energy with mobile,all-weather and efficient supply mode will open a new era of energy demand.As an energy device in the new era,Triboelectric nanogenerator（TENG）is a kind of device which collects energy in the environment based on piezoelectric effect,pyroelectric effect,triboelectric effect and electrostatic induction.It can collect the mechanical energy in the surrounding environment and convert it into electric energy to power small electronic devices,realizing the miniaturization and real-time energy supply.Besides,it has the advantages of low cost and wide selection of materials,etc.Compared with other energy conversion technologies,TENG has a higher low-frequency energy conversion efficiency,which makes Triboelectric Nanogenerator have a broad application prospect.Since the output power density is related to its surface charge density,many studies focus on improving the charge density.This paper studies material selection and circuit management to improve output performance and explore charge accumulation mechanism.PVDF-HFP was selected as the material to make the required film.However,when the output charge density increases to a certain extent,the output will be limited by the air breakdown,and the thickness of dielectric film and the size of dielectric constant are two factors affecting the air breakdown,so my main work is as follows:1.The high dielectric constant PVDF-HFP thin film is synthesized.Due to the ferroelectric property,the friction layer will form charge trap,and the electrogenicity is enhanced.The influence of dielectric film on the output current,output voltage and output charge under different conditions is compared.The results show that the decrease of the film thickness will lead to the increase of the output,but when the film thickness reaches6.8μm,the charge density will stop increasing or even decrease,because the film is too thin by stress damage,breakdown at high pressure,resulting in the escape of charge.At the same time.2.The output of the external excitation circuit which can realize the charge excitation strategy and the self-excitation circuit under the same external environment is observed and compared.Since the external excitation circuit has charge provided by TENG,the output of the external excitation circuit will be significantly improved under the condition of the same thickness film,about 1.53 times that of the self-excitation circuit.However,the rate of charge saturation of the self-excited film is obviously higher than that of the external excited film.In the case of the same 10nf capacitor,the rate of self-excited film saturation is 5 times that of the external excited film.At the same time,the larger the capacitance,the higher the rate of saturation charge density between the external charged excited film and the self-charged excited film.3.Charge excitation is realized by Triboelectric Nanogenerator.After charge excitation,the surface charge will accumulate and reach a high equilibrium state at the same time.Due to the polarization effect of ferroelectric materials in high voltage field,the output charge density reaches 1.84 mc·m-2.By using charge excitation,a relatively thick dielectric material layer can be used to achieve the effect of the previous ultra-thin dielectric material layer,so as to avoid the air breakdown and reduce the leakage current.The membrane can light a hythermograph and a small calculator,as well as 456 LED lights. |
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