Preparation Of Vanadium-based Electrode Materials For Supercapacitors And Its Electrochemical Performance

In modern society,people have a huge demand for clean energy such as electrical energy,but electrical energy is difficult to store,so new energy storage devices are essential to society.Supercapacitor is a kind of energy storage device with great potential,and it is the most promising to solve the future fossil energy scarcity crisis.In theory,vanadium oxide material has the advantages of higher specific capacitance and abundant resource reserves,and has become a widely used electrode material for supercapacitors.In this paper,the hydrothermal method was used to prepare Na V₆O₁₅and V₂O₅nanorods,and V₂O₅was doped with glucose as a carbon source to prepare V₂O₅/C composite materials.In the hydrothermal process,carbon is arranged in the reactor as a substrate,and the nanomaterials are grown on the carbon cloth,and finally the super capacitor electrode is made after annealing treatment.Use X-ray diffractometer（XRD）,field emission scanning electron microscope（SEM）to characterize the structure and morphology of the material,use cyclic voltammetry（CV）,constant current charge and discharge（GCD）and AC impedance spectroscopy（EIS）and other methods for electrochemical testing of materials.（1）Na V₆O₁₅ nanorods were prepared by hydrothermal method,and the effects of sodium nitrate addition and different annealing temperatures on the morphology and electrochemical properties of Na V₆O₁₅were studied.The uniform shape of Na V₆O₁₅nanorods with a diameter ranging from 30 nm to 100 nm and a length of 500 nm were prepared.In the hydrothermal preparation process,the carbon cloth is placed in the reactor as the base,the Na V₆O₁₅precursor is grown on the carbon cloth,and finally the carbon cloth is annealed to make Na V₆O₁₅carbon cloth with the carbon cloth as the current collector Electrode and its electrochemical performance analysis.When the current density of the electrode is 0.5 A/g,the specific capacitance is 735.3 F/g.After 3000 cycles,the capacitance retention rate is85%.（2）V₂O₅ nanoparticles were prepared by hydrothermal method,and the effect of V₂O₅addition on the morphology of the product and the effect of annealing temperature on the crystal structure of V₂O₅nanoparticles were studied.Prepared zero-dimensional nanoparticles with an average diameter of 80 nm.Using carbon cloth as the current collector,the precursor of V₂O₅nanoparticles was grown on the carbon cloth by hydrothermal method,and then the carbon cloth was annealed to prepare a V₂O₅carbon cloth electrode,which was electrochemically performed using a three-electrode system Performance analysis.The electrode has a specific capacitance of 678.6 F/g when the current density is 1 A/g.（3）The instability of the physical structure of the V₂O₅material leads to poor cycle performance of this material.In order to improve its performance,glucose is used as a carbon source to prepare a more uniform diameter from 50 nm to 80 through a hydrothermal method.For V₂O₅/C nanorods with a length of 300 nm and unequal nm,the effect of annealing temperature on the morphology of V₂O₅/C nanorods was studied.In the process of preparing the precursor of V₂O₅/C nanorods by hydrothermal method,the carbon cloth is placed as a substrate in the hydrothermal reaction system,the precursor of V₂O₅/C nanorods is grown on the carbon cloth,and the carbon cloth is annealed,Prepared into a V₂O₅/C composite electrode.A three-electrode system was used to analyze the electrochemical performance of the electrode.When the current density is 1 A/g,the specific capacitance of the electrode is 952 F/g.After 3000 cycles,the capacitance retention rate is 82%,which has a good.The magnification performance is always low impedance.