| The research of lithium ion electrode materials is the key to solve the current energy crisis and improve the potential of secondary energy system.Combining one-dimensional(1D)nanostructures with electrode materials can radically affect the performance of the electrode material.There are a variety of methods for preparing 1D electrode materials,including sol-gel,phase deposition,solution and so on.However,these methods can not achieve 1D nano-materials with highly ordered structure and the further development of these techniques practical routes to large quantities of 1D nanostructures from a diversified range of materials,rapidly,and at reasonably low costs,still requires great ingenuity.In view of these problems,this paper provided a method for the large scale preparation of various kinds of 1D nanostructure materials with highly orientation and regular structure by using AAO template,including metal,nonmetal and polymer nanowire materials.This fabrication process could be concluded as follow: The AAO template firstly was prepared by secondary anodic oxidation method.The melting(Such as bismuth),non-metallic(such as selenium)and polymer sol gel(such as polyacrylonitrile)were pressed into AAO nanopores temple by mechanical hydraulic force.After cooling and drying,the AAO template was removed to obtain the corresponding metallic,non-metallic,and polymer nanowire arrays material.The electrochemical properties of the prepared nanowire electrode materials were tested and the mechanism of Li-ion or Na-ion storage was studied.The preparation of metal bismuth(Bi)nanowires.The X-ray diffraction spectrum had showed that the Bi nanowires prepared by mechanical hydraulic method are with highly regular oblique hexagonal single crystal structures.The Bi-C nanocomposites were formed by continuous milling the prepared Bi nanowires and carbon black.In addition,the reaction mechanism of Bi/C nanocomposites used as anode materials in Li-ion and Na-ion batteries in the process of charge-discharge is proved by ex-situ XRD measurements.The results revealed that Bi follows an alloying mechanism with Li+ ions while an intercalation process for Na+ ions.The preparation of non-metallic selenium(Se)nanowires.The molten Se was injected into an AAO template and solidified to form Se nanowires.The thermal stability and electrochemical performance of Se nanowires were introduced and discussed in detail.The results show that the obtained Se nanowires have a lower melting point than that of bulk Se due to the size effect.During the charge-discharge process,there might be a phase transition between crystalline and amorphous,which prompted Se nanowires to exhibit a higherspecific capacity and better cycling life.This is of great significance for low cost,simple and convenient preparation of nonmetallic(S,Se,Te,etc.)with low melting point(< 650 ?)and its compound nanowire materials.The preparation of polymer nanowire arrays.The AAO template was also used to fabricate PAN nanowire arrays by mechanical hydraulic method,which provides a new idea for the preparation of polymer nanowires.By high temperature carbonization,the porous nitrogen-rich carbon nanowires could be directly obtained.They exhibited high initial capacities and favorable rate performance when nitrogen-rich carbon nanowires were used as Li-ion batteries anode material.Because of the porous carbon nanowire structure and the large amount of nitrogen doping,this nitrogen-rich carbon nanowire material also have unique advantages in catalysis,supercapacitors and hydrogen storage application potential. |
PDF Full Text Request