Triboelectric Nanogenerators Based On Gallium Modified Polymer Hybrid Fiber Membranes

With the rapid emergence of wearable/portable electronic products,the traditional large-scale energy harvesting technology can no longer meet the development needs of small/micro electronic devices.How to realize the self-power supply of small-scale system has become an urgent need for the development of electronic information.The emergence of triboelectric nanogenerators(TENGs)in 2012 brought dawn to the solution of this problem.Through the utilization of the phenomenon of triboelectricity,people have eliminated the long-standing negative impression of this effect and made it a new type of green energy.TENG mainly realizes the conversion and collection of energy through the coupling of triboelectric charging and electrostatic induction.At present,studies on TENG focus on performance improvement and practical application.It has been proved that doped nanoparticles generally have a better effect on the improvement of TENG output.However,the nanoparticles used are relatively expensive and only play a significant role in higher doping levels,which is unfavorable for TENG to go out of the laboratory and enter the market.In this regard,this paper proposes a method to improve the performance of TENG by using gallium as doped nanoparticles,which has nearly doubled output enhancement,and explores the role of gallium particles.The main achievements and work of the thesis are as follows:1. A feasible low-cost gallium metal doping process.Gallium has the characteristics of low melting point and supercooling.Therefore,it is easy to achieve the embedding of gallium nanoparticles in various polymer nanofibers through a simple liquid phase ultrasonic dispersion.This process is suitable for large-scale production due to the simple technology and low cost,and gallium has a lower price and lower doping amount than other doped particles,which make the overall cost can be further controlled and reduced.2. High performance polyacrylonitrile(PAN)modified TENG.Through the selection of different doping amounts,the study makes the energy output of TENG based on PAN fiber membrane nearly doubled.Among them,TENG with a thinner PAN/gallium particles composite membrane can achieve a current density of up to 50m A/m~2,a charge density of 260μC/m~2 and an output voltage of 600 V under the working conditions of 3 Hz and 30 N,which is significantly higher than other PAN-based TENG performance.3. The effects of working conditions on the performance of TENG with composite membrane structure are explored.We found that the current density and output voltage of TENG showed a trend of increasing first and then tending to saturation with the increase of operating frequency and contact pressure.Under the analysis of the transfer charge density,we understand the different roles of two movement conditions,so that TENG shows a different performance change range.4. The roles of gallium in PAN composite membranes are investigated.The doped gallium particles mainly achieve the improvement of TENG performance through charge trapping,but the doping of metal nanoparticles will cause the aggregation of the electrospun fibers,which results in the degeneration of TENG output.The two factors affect the triboelectric performance of TENG together,and lead to the phenomenon that the energy output increases first and then decreases as the gallium concentration increases.