| With the improvement of environmental protection awareness,supercapacitors have been widely recognized as a new type of low-cost,high-power density,long-life,clean and pollution-free energy storage devices,so they have good application prospects.On the other hand,with the continuous development of flexible and wearable electronic technology,small foldable electronic devices are entering our lives and become a trend in the future development of electronic devices.How to make these new flexible and foldable electronic devices a reality?It is necessary to develop flexible electronic energy storage devices that match it.It has been reported that the performance of supercapacitors is mainly determined by the electrode material.At present,commercial supercapacitors are mainly assembled with carbon materials,but supercapacitors prepared from carbon materials have low energy density and cannot meet the growing market demand.Therefore,the preparation of carbon materials with excellent electrochemical properties is one of the breakthroughs in solving the problem of supercapacitors.Based on this,three different types of porous carbon materials were prepared and assembled into solid supercapacitors.The prepared porous carbon materials and solid supercapacitors were studied by a series of characterization methods and testing methods.The main research contents are as follows:（1）Using the dung beetle forewing as the carbon source,a simple and low-cost method was used to prepare N self-doped porous carbon.The prepared porous carbon material has the advantages of large specific surface area and high porosity.The test results show that the specific capacitance of the porous carbon electrode based on the dung beetle forewing is as high as 348 F·g-1when the current density is0.5 A·g-1.Furthermore,the solid-state symmetric supercapacitor assembled from this electrode and KOH/PVA electrolyte shows high energy density and good cycling stability.Three solid supercapacitors connected in series can light up the red diode,indicating that the supercapacitor has potential application prospects in the field of energy storage.（2）In this part,the forewing of dragon louse was used as raw material,carbonized at high temperature,and then activated carbon material with KOH to prepare porous carbon,and the effect of KOH on the structure and electrochemical performance of porous carbon was studied.Studies have shown that in 6 M KOH electrolyte,when the current density is 0.5 A·g-1,the specific capacitance is as high as 379 F·g-1;when the current density is 20 A·g-1,the specific capacitance is still 255F·g-1,indicating that the electrode has good rate performance.In addition,a solid supercapacitor was assembled with electrodes based on this material.When lithium sulfate was used as the electrolyte,the power density was as high as 449.81 W·kg-1,and the energy density was 18.18 Wh·kg-1,and the supercapacitor had good performance.Stability(10,000 times of charge and discharge when the current density is 1 A·g-1,the capacitance retention rate is 92%).（3）In this part,covalent organic frameworks（COFs）materials were prepared using 1,4-pyrazinedicarbaldehyde and tris（4-aminophenyl）amine as building blocks,and porous carbon materials were prepared using the COFs as carbon source.Carbon materials based on COFs have large specific surface area,high porosity,and high N and O doping.Studies have shown that the electrode based on this material has a specific capacitance of 415 F·g-1at a current density of 0.5 A·g-1,and the assembled solid electrode has a specific capacitance of 288 F·g-1at 0.5 A·g-1.The energy density is 10 Wh·Kg-1. |
