Study On Preparation And Properties Of V₂O₅/CNT Free-standing Film Electrode

As a new type of energy storage device,supercapacitors have advantages of high power density and fast charging.It is widely used in the production of life,mainly in the field of consumer electronics,transportation,etc.But supercapacitors also face another major problem:the low energy density,which far cannot satisfy the demand of people.In recent years,in order to improve the energy density,researchers focus on synthesis of new materials,composite materials,ion doping,regulating the material structure.In this paper,we took vanadium pentoxide as the research object and systematically described the synthesis,characterization and electrochemical properties of the vanadium pentoxide ultralong nanobelts.At the same time,we developed a method of preparation of large scale V₂O₅/CNT free-standing film.The main contents are as fellows:1.We have developed a method of preparation of V₂O₅ ultralong nanobelts and characterized the morphology and structure of V₂O₅ ultralong nanobelts.2.Based on V₂O₅ ultralong nanobelts,we developed a method of preparation of large scale V₂O₅/CNT free-standing film electrode.This method is simple,low cost,universal.Besides,the mass density can be up to 2.5 g/cm³ after the V₂O₅/CNT free-standing film is pressed.This film electrode still maintains good flexibility and hydrophily,of which the initial contact angle is 28.5°.Then droplets can completely permeate the whole film in 6 seconds.This general strategy opens exciting new opportunities for construction of other oxides/CNT hybrid free-standing films for energy storage,catalysis,and other chemical and energy transformation processes.3.With V₂O₅/CNT free-standing film electrode,we prepared symmetric supercapacitors,and studied electrochemical properties.The symmetric capacitor based on two identical film electrodes displays a wide operation voltage window of1.6 V,delivers a volumetric energy density as high as 41 Wh/L,and maintains the good times and cycle stability.More significantly,it maintains high energy density?>25 Wh/L?at a power density of 2.2 kW/L.which is higher than carbon-based supercapacitor in the organic electrolyte.The high performance and large scalability of such film electrodes fabricated by cost-effective processes make it promising for practical applications.