Controlled Synthesis And Capacitance Performance Of Vanadium Pentoxide With Different Morphologies

As a new energy storage device, the most significant advantages of supercapacitor are high power density, energy density, long service time and pollution free. Compared with traditional batteries and capacitors, supercapacitor has a high commercial value. The V2O5 hollow microspheres and a new type of multilayer structure were synthesized in this work. The morphology structure of products were characterized by X-ray power diffraction, infrared radiation, scanning electron microscopy and transmission electron microscopy. Cyclic voltammetry and constant current charge-discharge were used to characterized the electrochemical properties of the materials. The main results are as follows:In the first part, we prepared the V2O5 hollow microsphere electrode materials by solvent thermal method, and discussed its formation mechanism. The capacitor properties were studied by cyclic voltammetry and constant current charge-discharge test. The results show that the type and concentration of electrolyte, voltage window, scanning speed and current density have effects on the capacitance performance of the V2O5 materal. Among them, in 1 mol·L-1LiNO3 electrolyte, under -0.4～0.6 V(vs.SCE) of voltage window,50 mV·s-1 of scanning speed and 1 A·g-1 of current density, the CV curves of the V2O5 hollow microspheres behave well symmetry. There are two pairs of redox peaks. The specific capacitance of electrochemical active material is 459 F·g-1. It has a better rate performance and shows an ideal capacitor performance.In the second part, to prepare a novel structure of multilayer V2O5, we used a simple and environmentally friendly hydrothermal method. It is rarely reported in the organic or water system. We text the capacitor properties of the electrode made from multilayer V2O5, cyclic voltammetry and constant current charge-discharge test were used. Among them, in 1 mol·L-1 LiNO3 electrolyte, under -0.4～0.6 V(vs.SCE) of voltage window,50 mV·s-1 of scanning speed and 1 A·g-1 of current density, the cycle stability of the V2O5 material is excellent, and the specific capacitance of the electrochemical active material is up to 296 F·g-1. It provides a new idear for the development of new electrode materials for supercapacitors.