A Mutually Beneficial Hybrid Cell Based On Dielectric Elastomer Generator And Triboelectric Nanogenerator For High-Efficiency Energy-Harvesting

In the era of the Internet of Things(Io T),ubiquitous sensor network nodes bring convenience to both daily life and industrial production while facing huge energy supply challenges.Batteries as the primary choice of conventional energy supply exhibit apparent drawbacks such as the limited lifespan that needs frequent replacement or recharging,large volume and weight,rigidity,biological incompatibility,and environmental pollution.Thus,ambient energy harvesting technologies could be attractive solutions to replace batteries.Among various energy types that exist around the environment,mechanical energy could be one of the most promising energy sources to build self-powered sensor networks,which is widely distributed but normally wasted.In recent years,scientists have devoted great efforts to exploring ambient mechanical energy harvesting technologies to produce electricity,including dielectric elastomer generator(DEG),triboelectric nanogenerator(TENG),piezoelectric nanogenerator(PENG),electromagnetic generator(EMG),and so on.TENG based on the coupling of triboelectrification and electrostatic induction effects holds promise as a viable power source and can directly convert low-frequency mechanical energy into electricity.In addition,the output characteristics of high opencircuit voltage are also well applied in scenarios where high voltage is required,for instance,electrostatic spinning.Triboelectric nanogenerators and dielectric elastomer generators are potential highly effective energy conversion technologies thanks to their similarity in electricity generation mechanism and transmission but still have limited use due to their intrinsic essential,including air breakdown effect for TENGs and external polarization voltage requirement for DEGs.In order to overcome these drawbacks and to design a novel scavenger with a higher output energy density,we propose herein to couple TENG with DEG(named as TDHG).In this configuration,the charge produced by TENG due to external mechanical excitation is employed as polarization source of the DEG,so that DEG can completely harvest energy.At the same time,DEG has no airgap characteristics to compensate for the decrease in output of TENG due to the air breakdown effect,which can promote the output performance of the hybrid system to a higher stage.Under the corresponding theoretical support,the effect of many factors,including pre-stretching ratio of the dielectric elastic membrane,amplitude of sinusoidal motion,operation frequency,external capacitance in the self-excitation circuit,etc.,on the output performance of our TDHG system are systematically studied.After optimization,the charge of TENG,DEG,and TDHG can reach up to 1.03,3.03,and 5.05?C,respectively.Furthermore,under the same conditions,the charge output of DEG is about three times that of TENG,which highlights the advantage of no air gap between the electrode and the dielectric film.This work proposes a new design concept of hybrid energy harvester and has great significance to promote the practical applications of DEG and TENG as portable power generators with excellent energy harvesting performance.