Research On Structure Optimization And Energy Harvesting Application Of Triboelectric Nanogenerator Based On Solid-liquid Interface

The environment contains abundant mechanical energy with small relative energy,small motion range and irregular motion,which cannot be effectively collected by traditional electromagnetic generators.Triboelectric nanogenerator(TENG)is an effective way to convert mechanical energy into electrical energy based on the coupling principle of triboelectric generation and electrostatic induction effect.Raindrop energy,which exists in tiny,discrete forms,is widely distributed in nature.Because of the novel working principle of the friction nanogenerator,water itself can be used as a friction material,which can electrify the surface when rubbed against the surface of the polymer dielectric material.An electric current is induced in the electrode as the water drop or wave moves.Based on these characteristics,this paper studies the efficient droplet energy collection of solid-liquid friction nanogenerators from three aspects:structure optimization,morphology optimization and practical application.The specific work and results are as follows:Three solid-liquid friction nanogenerators(SE-WTEG,BE-WTEG and EE-WTEG)with different electrode structures were designed.The optimum output condition of WTEG system is explored by adjusting the variables of inclination Angle and drop height to improve the power output and energy conversion efficiency.The results showed that the EE-WTEG output performance was significantly better than BE-WTEG and SE-WTEG,with peak Voc value of 27.82v,Isc value of 5.63a,maximum load power of 132.25w and optimum inclination Angle of 20°.In addition,the observation of the cumulative charging behavior of continuous droplets further broadens the understanding of the charging mechanism to maximize the charge storage capacity of the generator.In the simulated rainfall experiment,the maximum power density of EE-WTEG is 1.838w/m2 and 30 LEDs can BE lit,which proves that BE-WTEG has a broad application prospect in rainwater collection.Secondly,a variety of PDMS films with micron array structure were prepared on the silicon template by scraping and coating method.The results show that the PDMS film morphology,structure,size and film thickness show different output performance,among which,the square column structure has the best output performance,and the output performance decreases gradually with the increase of film thickness.Finally,a custom solar cell with sunlight and raindrop energy was demonstrated by implanting a PDMS layer onto the surface of an Si solar cell with an Al/Si/Agl/PDMS/Ag2 structure.By systematically optimizing the performance of PDMS films,the physical proof-of-concept device can significantly improve the power conversion efficiency from the original 17%to 21.2%due to the reduced Fresnel reflection loss during a single solar exposure.Surprisingly,because TENG’s charge distribution on the back electrode is modulated,A peak short circuit current(Isc-t)of about 7.71 A and A peak open circuit voltage(Voc-T)of about 40.1 V are achieved between the two.Stimulated by a raindrop,the Al electrode at the bottom and the Ag2 electrode at the top simultaneously lit up 26 commercial green light-emitting diodes(LEDs),indicating the greater potential of the traditional single-electrode or Ag/PDMS/Ag modes.Given the significant advantages of improved power output and extended operating time,the reported raindrop-specific device may provide a way to harvest all kinds of energy from the environment and facilitate the development of all-weather solar cells.