Design And Application Of Constant-voltage Triboelectric Nanogenerator

With the rapid development of the Internet of Things（Io Ts）,Big data and artificial intelligence,numerous small and low-power electronics are widely used.The traditional centralized power supply system cannot meet the energy needs of distributed and mobile electronics.In recent years,based on the coupling effect of contact electrification and electrostatic induction,triboelectric nanogenerator（TENG）can collect low-frequency and random mechanical energy from the environment to electricity,which is a promising technology in high-entropy energy supply.However,the output performance and durability of TENG are crucial issues that limit its development and application.Compared with the conventional pulse-output TENG（PV-TENG）,constant-voltage TENG（CV-TENG）has the advantage of continuous and stable output,higher energy output efficiency and faster charging rate for energy storage devices.This dissertation focuses on the systematic research of CV-TENG.Starting from the structure design of CV-TENG,to the performance enhancement,then to the construction of efficient energy transport system based on CV-TENG,and finally to the application of the energy harvesting and self-powered sensing based on CV-TENG.The main researches of this dissertation are as follows:1.Based on the precise phase-shift design realized by 3D printing technology,a rotating-freestanding TENG array（RF-TENG array）with low crest factor is prepared.The quantitative relationship between the optimal phase shift,the number of phases and the crest factor is established.And the result reveals that phase-shift design can regulate the crest factor of the output.The influence of structural parameters on the output of RF-TENG array is investigated.Through structural optimization,the crest factor of the RF-TENG array is reduced to 1.07 and achieves the constant-voltage output.With the low-wear characteristics of adaptive contact mode,the output of the RF-TENG array remains 80%after 1.2 million cycles.This work provides the guidance for the design of the CV-TENG.2.A non-contact CV-TENG via charge excitation（ECV-TENG）is proposed.By integrating the optimal phase-shift design with charge pump and non-contact structure,the output and durability of CV-TENG are improved simultaneously.Through the optimization of motion conditions and structure parameters,the ECV-TENG achieves the average power density of 12.74 W m^-3 Hz^-1.The coupling of the adaptive contact mode with low wear and the non-contact mode with no wear enhances the stability of ECV-TENG,which remains the output of80%after 2 million cycles.In addition,by adopting the hydrophobic materials and non-contact structure,ECV-TENG shows the stable output in the humidity range of 40%-85%,meaning the good humidity resistance.This work provides an effective method to improve the output and durability of CV-TENG.3.The dynamic energy transport process of CV-TENG from environmental mechanical energy to electricity application is investigated.The influence of the CV-TENG and type of load capacitor,and the discharge voltage on the energy output of each node and link in energy transport process is studied.On this basis,a real-time intelligent energy optimization system（RIEOS）is constructed,which consists of three main parts:a CV-TENG for efficient charging process for capacitors,a low leakage-current capacitor at high voltage to reduce energy loss in energy transport process,and an energy management module for releasing stored energy of capacitors at the optimal voltage to achieve the maximum energy output of CV-TENG.RIEOS can achieve all-day efficient energy transport in complex environments.Compared to a normal system,the energy transport efficiency of RIEOS improves the nearly 6.91 times.This work provides an effective strategy the development and application of CV-TENG from a system integration optimization perspective.4.A combination system of wind energy harvesting and wind speed sensing（EHSS）based on charge-excited non-contact CV-TENG is designed.Through the optimization and integration of each module in the system,the efficient energy transport of the system is achieved.By optimizing the triboelectric material pairs of pumping TENG,structure parameter of main TENG and energy management circuit for maximizing energy output,the EICV-TENG achieves an average power output of 0.26 W m^-2 Hz^-1 and the energy output efficiency of96%.At the wind speed of 7 m s^-1,the EHSS system stably powers 32hygrothermographs connected in parallel.The EHSS system can also realize real-time wind speed monitoring through the high linear relationship between the current frequency of single-phase pulse output and wind speed.This work provides a successful example for the design and application of CV-TENG for efficient energy harvesting and self-powered sensing,and promotes the further development and progress of TENG technology in the Io Ts.