Controllable Preparation And Electrochemical Properties Of Vanadium Oxide Electrode Materials

The large-scale use and exploitation of fossil energy by human beings has led to a sharp decline in the reserves of globalized stone energy,and at the same time,the environmental problems have become worse and worse,and the living conditions of human beings are worrisome.In order to alleviate the pressure on the environment and energy,the development of new energy systems is a top priority.New energy sources mainly include solar energy?biomass energy?hydro energy?wind energy?geothermal energy?wave energy?ocean current energy and tidal energy.These new energy sources are huge,but it is difficult to achieve large-scale applications.The main reason is that these new energy sources are affected by time and place.Limitations of other factors.Therefore,it is especially important to develop excellent energy storage devices to collect these huge energy sources.Among many energy storage devices,lithium ion batteries have attracted attention due to their high operating voltage,high energy density,long cycle life,and low self-discharge.Lithium-ion batteries have also been widely used in aerospace,automotive,home appliances and other fields,bringing a lot of convenience to the development of society.In the past two years,zinc-ion batteries have attracted significant scientific and technical interest from researchers due to their high safety,high ion conductivity and high rate performance.Whether it is a lithium-ion battery or a zinc-ion battery,the electrode material of the battery is the main component.The quality of the battery electrode material will directly affect the electrochemical performance of the battery.Therefore,it is extremely meaningful to prepare an excellent energy storage material.This thesis mainly studies the electrochemical performance of V₂O₅ electrode materials for lithium ion batteries and zinc ion batteries and the electrochemical performance of V₃O₅ electrode materials for lithium ion battery anodes.The first chapter briefly introduces the development of batteries and the structure and working principle of lithium-ion batteries and zinc-ion batteries.The research progress of common electrode materials for lithium-ion batteries and zinc-ion batteries is summarized.Finally,a brief introduction to the topic selection and research content of this thesis is given.The second chapter mainly introduces the experimental reagents and instruments used in the experiment,as well as the characterization methods of battery electrode materials,the assembly process of lithium/zinc ion button batteries and their electrochemical testing techniques.In the third chapter,a three-dimensional porous V₂O₅ is prepared by sol-gel method.The size of the material is about 3-10?m,which is a nano-micro composite structure,which not only ensures the contact area with the electrolyte but also ensures the stability of the structure.For lithium ion batteries,the electrochemical performance is greatly improved.In the fourth chapter of this thesis,the three-dimensional structure V₃O₅ is prepared by vacuum calcination.The material is about 1-3?m,which is a three-dimensional block structure.It is used for lithium ion battery anode materials to exhibit excellent rate performance,mainly due to three-dimensional.The open framework structure determines the fast reaction kinetics.In the fifth chapter,three-dimensional porous V₂O₅ was prepared by sol-gel method,which was used as cathode material for zinc ion battery.We demonstrate the feasibility of the 3D porous structure?3D-NRAs-V₂O₅?constructed by V₂O₅ nanorods as the positive electrode of ZIB.3D-NRAs-V₂O₅ can be scaled to kilograms by a simple sol-gel reaction followed by high-temperature calcination.The synergistic effect of the 3D porous framework and the layered structure of 3D-NRAs-V₂O₅results in easier detachment/embedded storage of Zn²⁺.The sixth chapter summarizes the work and explains the shortcomings in this paper and the prospects for future work.