SnO2填充碳纳米管电化学储锂研究

合成了SnO2颗粒填充多壁碳纳米管并对其储锂性能进行了初步研究.用透射电子显微镜(TEM)和X射线粉末衍射仪(XRD)分析其微观形貌和晶体结构,并与用硝酸纯化的多壁碳纳米管、SnO2颗粒包覆多壁碳纳米管进行比较.SnO2多数填充入碳纳米管管腔内.填充于碳纳米管内的SnO2与包覆在多壁碳纳米管外壁的SnO2晶体结构相同(JCPDS 41-1445).SnO2填充碳纳米管的放电容量可达284.2 mAh/g,高于纯化的碳纳米管(193 mAh/g)和SnO2包覆碳纳米管(82 mAh/g),具有SnO2的高放电容量和碳纳米管的低放电电位的优势.

Study of electrochemical lithium storage performance of the carbon nanotubes filled with SnO2

MWCNTs filled with SnO2 nanoparticles were prepared via hydrothermal reaction of purified MWCNTs in iron nitrate solution and subsequent calcination.The SnO2 nanoparticles inside nanotubes has the same structure as the SnO2 particles coating the outside wall of MWCNTs.The purification and oxidation treatment of MWCNTs in concentrated HNO3 solution contributed to the formation of open tips and surface functional groups, which were beneficial to the entrance of SnCl4 by capillarity as well as the adsorption and nucleation of tin oxide inside nanotubes.Electrochemical lithium storage performance was studied preliminarily on the obtained samples. MWCNTs filled with SnO2 nanoparticles were shown to have a higher electrochemical reversible capacity than both MWCNTs coated with SnO2 and MWCNTs purified by HNO3 during the charge and discharge process,which possessed the advantages of both higher discharge capacity of SnO2 and lower discharge potential of MWCNTs.Moreover,MWCNTs can accommodate the larger structure strain of SnO2 nanoparticles inside nanotubes produced during Li-ion insertion and extraction, which may improve the cycle stability of the electrode to a certain extent.