Preparation Of Carbon Nanotubes And Carbon Nanotubes/graphene Macroscopic Body And Their Energy Storage Properties

In 1991,after the discovery of multi-walled carbon nanotubes(MWCNT)the world set off a research upsurge of carbon materials again after C60.Carbon nanotube(CNT)has a unique quasi one dimensional hollow structure,large specific surface area,excellent mechanical properties and good conductive properties properties.These properties aroused great interest of scholars at home and abroad and made it has great potential application prospect in various fields.The two-dimensional graphene(G)has the advantages of light quality,excellent electrical performance,good thermal conductivity and large specific surface area.It attracts the attention of researchers with unique properties and is widely used in advanced materials and devices.Although the electrical and mechanical properties of CNT and graphene are similar,there are many differences in the structure of them.The electrolyte diffusion efficiency and charge transfer of graphene sheets in vertical direction are low.The CNT with small curvature radius,active substances are difficult to achieve high density load.The boundaries of carbon nanotubes will hinder the charge transport.Therefore,them have been greatly restricted in the application of energy storage materials.In order to solve these problems,we can take the appropriate methods to form a three-dimensional structure,and to improve the specific surface area and its electrochemical properties to prepare the ESC electrode material with excellent electrochemical properties.In this paper,the preparation of electrode materials was based on CNT and graphene.And the electrochemical properties of the electrode materials were also studied.By using X-ray diffraction(XRD),laser Raman spectroscopy(Raman),scanning electron microscopy(SEM)and N2 adsorption-desorption analysis means to investigate materials’ structure,composition and morphology.The electrochemical properties of materials were measured with battery tester and electrochemical workstation.The details are as follows:1.First,CNT was processed by acid.Then used the reflux-filtration method to prepare carbon nanotube with network structure(CNTNWS).Then characterized the electrochemical properties of the two kinds of materials.The results showed that CNTNWS prepared after the secondary growth of CNT had better electrochemical properties.Its specific capacity value can reach 118 F/g.And it had a good life cycle stability.2.By using chemical vapor deposition(CVD)to prepare graphene on nickel foam substrate.After the next dipping treatment,the CNT/G was prepared by growth of CNT on graphene.Then investigated the morphology,and measured electrochemical properties of materials by assembling ESC with CNT/G electrode.The experimental data results showed that CNT/G had a more excellent electrochemical performance,and specific capacity reached 104.44 F/g.And it had the advantages of low resistance and good life cycle stability.3.The CNT was unzipped by oxidation to prepare CNT/GO.Then ascorbic acid(LAA)was used as reductant.After the reduction macroscopic body—CNT/RGO was prepared by freeze-drying.And its electrochemical properties were investigated.The experimental results showed that the electrochemical performance of CNT/RGO had been greatly improved.The specific capacity reached 128F/g.And it had a good life cycle stability.