Design And Preparation Of Biomass-Based High-Performance Electrode Materials

In the current environment of excessive resource consumption,resources have been exhausted and cannot normally supply the needs of contemporary social development.In the past two hundred years,fossil energy has been used extensively by human beings,resulting in the exhaustion of fossil energy,which has caused great environmental pollution,affected the ecology and posed a threat to human health.Therefore,it is an urgent task for contemporary researchers to find new sources of energy.Researchers are working to find environmentally friendly renewable energy sources and storage facilities that are not fossil-based.The concept of new energy has been put forward in the 1980s.At the beginning of this century,new energy has gradually entered the production and life of human beings.Today,new energy such as solar energy and biomass energy has been widely used in production and life.Therefore,biomass materials have been favored by researchers,because biomass materials have many advantages such as large yield,no pollution,renewable,low price and so on.Biomass carbon materials have the advantages of diverse pore size,large specific surface area,good electrical conductivity and so on,which makes it have great energy storage value.In this thesis,CoSe₂/Aspergillus oryzae carbon material was prepared by high temperature calcination method,and CoSe₂,CoSe₂/activated carbon,CoSe₂/carbon citrate and CoSe₂/carbon glucose were synthesized as reference samples.By comparing the morphology,structure and characteristics of materials,it is found that biomass-derived carbon materials have excellent morphological characteristics and relatively good pore size distribution.Five kinds of materials are used as positive electrode materials for lithium ion batteries.Compared with other ordinary carbon materials,biomass-derived carbon has N and P heteratom doping,which provides more active sites for lithium ion Mosaic and increases the material capacitance.It is beneficial to the reaction of the battery and significantly improves the electrochemical performance of the battery.Secondly,we prepared S/Aspergillus Niger carbon composite material by simple coprecipitation method,and prepared S,S/activated carbon,S/carbon citrate as reference samples,and used them as cathode materials of lithium sulfur battery to study its electrochemical performance.The surface of Aspergillus Niger has a large number of folds,so the S/Aspergillus Niger carbon has a larger specific surface area.When S/Aspergillus Niger carbon composite material is used as the cathode material of lithium sulfur battery,the carbon shell of Aspergillus Niger has a large number of mesopoles to provide a large number of channels for the free shuttle of ions,which is conducive to the electrochemical reaction rate and can significantly improve the electrochemical performance.It can be considered that S/Aspergillus Niger carbon is an excellent cathode material for lithium sulfur battery.Finally,CoP/Aspergillus oryzae carbon composites were prepared by biological in situ composite and high temperature calcination,which is a simple and green synthesis strategy.N and P elements contained in biomass contribute to N and P heteroatomic doping of carbon materials.Using the characteristics of biomass self-assembly,transition metal elements were loaded into Aspergillus oryzae spores,phosphorus elements of biomass were used as phosphorus source to prepare CoP/Aspergillus oryzae carbon,and single CoP,CoP/carbon citrate and CoP/activated carbon were prepared as reference samples.The supernano transition metal phosphatide crystals were uniformly embedded into the carbon base of the hollow bowl of Aspergillus oryzae,and the basic physical characterization of the material was carried out.The material was used as anode material of potassium ion mixed capacitor for electrochemical performance test,realizing rapid electron/ion transport.The hollow bowl structure of Aspergillus oryzae and the distribution of mesoporous pores were beneficial to the reaction of the battery.It can improve the electrochemical performance of batteries and is a promising anode material in potassium ion hybrid capacitors.