中文摘要：

以KMnO4、HCl为反应物，H2SO4、NH4Cl为助剂，利用水热法成功合成了α-Mn02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CI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相转化为口相；NH4＋可以起到维持产物晶型（a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mMn02纳米管微球作为锂电负极具有高容量（20mA·g-1电流密度下首周放电比容量达1783．5mAh 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。

英文摘要：

Self-assembled microspheres of a-MnO2 nanotubes were successfully synthesized by hydrothermal method using KMnO4 and HCI 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 CI- ion concentration decreases the diameter of nanotubes but increases their length. In contrast, increasing both H＋ and Cl- ion concentrations, changes the product from a phase to β 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.