A Research On Electrode Characteristics Based On Biomass Electrode Material

With the increasing demand for energy in human society,electrochemical energy storage devices have entered people's vision.Such energy storage devices play an important role in human's daily life,and are widely used in transportation,power transmission,laser weapon manufacturing and portable equipment applications.Electrochemical energy storage device,the choice of electrode material is of vital importance to determine the electrochemical performance of the device.Therefore,it has become a hot topic in this field to search for electrode materials with good performance and environmental protection and safety.In this paper,a kind of small molecule quinone biomass juglone,which is renewable and has certain oxidation-reducing property,was studied.?1?The small molecule of juglone was extracted from walnut peel by cold extraction and ultrasonic extraction.Then the juglone was coated on the carbon fiber sheet to prepare electrodes,and the electrodes were tested for cyclic voltammetry,galvanostatic charge-discharge test,and electrochemical impedance spectroscopy test.The results showed that the capacity of juglone electrode was 61.4 F g^-1 under the current intensity of 5 mA,and the problem of dissolution occurred during the test,resulting in the low cycle life of juglone material,which needed to be improved.?2?Using p-toluene sulfonic acid as dopant,the juglone/polypyrrole complex was prepared by electrochemical copolymerization under the condition of constant current.The results showed that the polypyrrole was polymerized successfully and covered compactly on the surface of juglone material.The structure was beneficial to increase the contact sites and reduce the material loss during the reaction process.The results of cyclic voltammetry,galvanostatic charge-discharge test,and electrochemical impedance spectroscopy test show that the specific capacity of 1.2 A g^-1 can reach 152.4 F g^-1,which is more than twice as high as that of the single walnut quinone.After 1000 cycles,87.6%of the original capacity was retained.?3?polypyrrole was successfully polymerized on the surface of carbon nanotube particles by in-situ polymerization,and then it was compounded with juglone by physical blending.Experiments,discusses the complex join proportion and other process parameters influence on the performance of the composite,the complex was characterized by morphology observation and infrared spectroscopy,and then its capacity,cycling performance and coulombic efficiency were analyzed by cyclic voltammetry test and galvanostatic charge-discharge test,and its frequency response characteristics were analyzed by electrochemical impedance spectroscopy test.Through the analysis,the mixture ratio of juglone and polypyrrole/carbon nanotube complex was1:1,with larger capacity(up to 259.7 F g^-1 at 0.5 A g^-1)and good cycling performance?80.6%of the initial capacity was maintained after 2000 cycles?.When the composite electrode material prepared under this experimental condition was assembled into a symmetrical supercapacitor,it also showed good cycling performance?81.4%after2000 cycles?and good electrochemical performance(10.9 W h kg^-1 at a power density of 0.16 kW kg^-1).