Design And Performance Improvement Of All-in-one Energy Harvesting And Storage Devices Based On TENG And Dielectric Capacitors

With the emergence of artificial intelligence and big data,human society has entered the"Age of Wisdom."However,the potential problems arising from the rapid development of society cannot be ignored.On the one hand,how to power billions of microelectronic devices has become a key problem restricting social development;on the other hand,the problem of environmental pollution caused by the rapid consumption of traditional fossil energy has become increasingly prominent.Therefore,the development of green and renewable energy is not only an urgent need of the Internet of Things era but also a huge driving force for the development of modern information science.In recent years,piezoelectric nanogenerator and triboelectric nanogenerator(TENG),which are derived from the second term of Maxwell’s displacement current based on the characteristics of media polarization,have attracted widespread attention due to their advantages in high entropy environmental energy harvesting.There is also a growing number of all-in-one energy harvesting and storage systems designed based on TENG.However,most of these designs use batteries or supercapacitors as energy storage elements,which leads to bulky and complex structures in the designed devices.Meanwhile,its slow charging and discharging process and low output power density severely limit the application of TENG in the field of high-voltage pulse power.Given this,this paper focuses on the design of all-in-one energy harvesting and storage devices.Firstly,dielectric capacitors with a super-fast discharge rate and higher power density were introduced as the energy storage element.Combined with the advantages of the high voltage of TENG,an all-in-one energy harvesting and storage device was designed,and pulse output was realized through a power management circuit.Secondly,by integrating a rotary TENG and a half-wave rectifier circuit,the stable high-voltage output was generated and the high-voltage pulse discharge was realized.The main research contents of this paper are as follows:Chapter 3 introduces an all-in-one energy harvesting and storage device based on TENG and dielectric capacitors.Firstly,Poly(vinylidene fluoride-co-hexafluoropropylene)(P(VDF-HFP))membrane with uniform thickness and marvelous surface quality was prepared by the solution pouring method,which has excellent energy storage performance by performance tested.P(VDF-HFP)membrane dielectric capacitors were integrated with a contact-separated TENG by sharing electrodes.At the same time,the dielectric capacitors and high-voltage rectifier diodes constituted a voltage multiplying circuit(VMC),and the output voltage was significantly improved.The maximum voltage of the output storage capacitor can reach 2800 V.Subsequently,a buck DC-DC down converter was realized by the high voltage discharge switch,which can convert the stored high voltage pulse into the steady DC low voltage and be matched with the electronic system.And a scientific calculator and a laser diode were successfully driven.Finally,the structure was further optimized to realize the 1×1 cm~2 small device.At a vibration frequency of 75 Hz,the maximum voltage of the energy storage capacitor can reach 271 V.The pulse energy can meet the demand of low-power applications in specific scenarios,which explores a feasible way for the miniaturization design of nanogenerators.In addition,the detailed analysis of the measuring process,combined with the electrometer,electrostatic voltmeter,and other instruments,found the deviation of the open-circuit voltage measured by the electrometer in the experiment,which has a certain reference value for the subsequent accurate evaluation of the output performance of TENG.This work not only provides a new idea for the production of all-in-one energy harvesting and storage devices with excellent output performance but also makes a preliminary exploration for promoting the application of TENG in pulse power devices,and makes an important step for the practical application of TENG in miniaturized electronic products.In the above work,because the two electrodes of the contact-separated TENG are not on the same plane,the device output is unstable due to the need for wiring.Therefore,an all-in-one energy harvesting and storage device based on a rotary TENG and a half-wave rectifier circuit was designed in Chapter 4.The rotating TENG was designed using soft rabbit hair and Fluorinated ethylene propylene(FEP)film as the friction layer to achieve soft contact,which not only can reduce the wear generated during movement and improves the stability of the device but also can significantly improve the output performance of the device through multiple energy conversion cycles in a single cycle of mechanical movement.And we studied and analyzed the effects of different materials and the logarithm of complementary electrodes on output performance.By using FEP film,the logarithm of complementary electrodes of 4,and the rotation rate of500 rpm,the device can generate open-circuit voltage,short-circuit current,and transferred charge of 560 V,84μA,and 390 n C.Subsequently,an all-in-one energy harvesting and storage device was prepared by integrating the rotating TENG with the half-wave rectifier circuit.Under the condition that the storage capacitor is 10 n F,the maximum output voltage can reach 3000 V,and the highest single-cycle captured energy can reach 1580.46μJ.A high-voltage pulse discharge was realized and significant electrical sparks can be observed.This work not only produces a rotary TENG with high energy conversion efficiency but also designs an all-in-one energy harvesting and storage device by integrating with a half-wave rectifier circuit to produce a stable high-voltage output,which makes a meaningful exploration for the application of TENG in the field of the high-voltage pulse.