中文摘要：

采用化学共沉淀法，以硫酸盐为原料，氨水为络合剂，NaOH为沉淀剂，制备得到颗粒均匀的镍钴锰氢氧化物Ni0.5Co0.2Mn0.3（OH）2前驱体，通过跟Li2CO3混合烧结后得到类球形的LiNi0.5Co0.2Mn0.3O2。采用热重分析（TG）、X射线衍射（xRD）、扫描电镜（SEM）对样品的结构、形貌、粒径分布进行表征，并利用恒流充放电测试对材料的电化学性能进行了分析。结果表明，在pH值=11．5的条件下制备得到的前驱体，与Li2CO3混合后，900℃下烧结后的正极材料，球形形貌规整，具有层状结构和优异的电化学性能，首次放电比容量达159mAh／g，60次充放电循环后放电比容量为147．1mAh／g，容量保持率为92％。可见所制备的LiNi0.515Co0.2Mn0.3O2材料具有高放电比容量、良好的循环性能和结构稳定性。

英文摘要：

Spherical LiNi0.5 Co0.2 Mn0.3O2 was prepared by calcining a stoichiometric mixture of Li2CO3 and Ni0.5 Co0.2Mn0.3O2（OH）2 precursor. The precursor was synthesized via a co-precipitation route with sulfate as raw materials, NH3 · H2O as complexing agent and NaOH as precipitant. The crystalline structure, morphology were analyzed using X-ray diffraction （XRD）, thermogravimetric analysis （TG）, scanning electron microscope （SEM）. And the effects of the pH value and calcination temperature on physical and electrochemical properties of the samples were deeply investigated. The cathode material with the well-ordered structural was obtained at the optimum synthetic conditions of the pH value 11.5 and the calcination temperature of 900 ℃. At the same time, the resultant powder of LiNi0.5Co0.2 Mn0.3O2 delivered a high discharge capacity of 159 mAh/g at 0.1 C, and excellent capacity retention of 92 % was retained after 60 cycles.