以KMnO4、HCl为反应物,H2SO4、NH4Cl为助剂,利用水热法成功合成了α-MnO2纳米管自组装微球.并采用X射线晶体衍射(XRD)、场发射扫描电子显微镜(SEM)、透射电子显微镜(TEM)以及X射线光电子能谱(XPS)表征手段对产物进行了形貌和结构表征,发现H+与Cl-离子浓度对产物的晶型有很大影响:单一增加H+或Cl-离子浓度可以使纳米管管径减小、长度增加;同时增加两种离子浓度则产物从α相转化为β相;NH4+可以起到维持产物晶型(α相)以及管状形貌的作用.电化学性能测试表明,具有独特形态的α-MnO2纳米管微球作为锂电负极具有高容量(2O mA·g-1电流密度下首周放电比容量达1783.5 mAh.g-1)与良好的倍率性能,是具有广阔应用前景的锂离子电池材料.%Self-assembled microspheres of α-MnO2 nanotubes were successfully synthesized by hydrothermal method using KMnO4 and HCl as reactants,and H2SO4 and NH4Cl as auxiliaries.X-ray diffraction (XRD),scanning electron microscopy (SEM),transmission electron microscopy (TEM),and X-ray photoelectron spectroscopy (XPS) were used to characterize the structure and morphology of the products.The H+ and Cl-ion concentrations substantially influence the crystal form of the product.Increasing either H+ or Cl-ion concentration decreases the diameter of nanotubes but increases their length.In contrast,increasing both H+ and Cl-ion concentrations,changes the product from α phase toβ phase.Moreover,NH4* ion plays the key role of maintaining the product crystal and its tubular morphology.The electrochemical performance results showed that the microspheres of α-MnO2 nanotubes with a unique morphology have a high first cycle discharge capacity of 1783.5 mAh·g-1 at the current density of 20 mA·g-1,along with a good rate performance.This suggests that the self-assembled microspheres were a promising material for lithium-ion batteries.
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