Preparation And Electrochemical Properties Of Energy Materials Based On Bacterial Cellulose

Bacterial cellulose has good designability due to its unique nanofiber network structure,and the high strength,rich hydroxyl functional groups on the surface of the fiber provide sufficient possibilities for it as an excellent self-supporting and flexible matrix.Wide range of sources,low cost,non-toxic,environmental protection has become a favorable factor for its rapid development.Its one of the main applications in the field of energy materials is to load active materials on bacterial cellulose substrates or to prepare activated carbon materials as electrode materials.In this paper,three kinds of samples were prepared by coating polypyrrole active material on the surface of bacterial cellulose nanofibers,pyrolysis of polypyrrole/bacterial cellulose composite carbon source,and pyrolysis carbonization of bacterial cellulose aerogel for copper ion adsorption material.The related material properties and electrochemical properties were characterized.The main research contents are as follows:(1)Exploring the best method for preparing PPy coated BC nanofiber electrode materials,and adjusting the concentration factor to obtain a high load electrode material with a load per unit area of 12mg,which has stable rate performance and good area specific capacitance(964mF cm-2,1 mA cm-2).And the sample also has good performance after widening the window to 2.0 V,and increases the energy density to 97.4 ?Wh cm-2(4.2 mW cm-2).After 10,000 cycles,the capacity loss is within 15%,which overcomes the long-term service life of conductive polymers.(2)Using the material obtained from(1)as the carbon source,the nitrogen-containing carbon nanofiber material was prepared,and the optimum conditions of the temperature and the performance improvement by the activation process were explored.The morphology,structure analysis and electrochemical performance of carbon materials with nanofiber structure were characterized.Finally,the specific capacities of optimum sample were 289 F/g(0.5 A/g)and 200 F/g(20 A/g)at 800? and 1:5 alkali carbon ratio activation.And with the increase in the number of cycles,there is a gradual improvement.(3)Using PVA blending and chemical grafting methods respectively,the modified bacterial cellulose aerogel material with excellent adsorption capacity for copper ions was obtained,which was the highest in 5 mg/L copper ion simulated waste liquid(EDA-BC).It can achieve an adsorption efficiency of 63.7%.After the adsorption material is separated and treated by carbonization high temperature treatment,a Cu/CuO-loaded carbon-based material having a high specific ratio and high specific capacitance(119.9 F/g,20 A/g)can be obtained and used for a supercapacitor electrode material.