中文摘要：

采用共沉淀-高温固相法合成正极材料LiNi0．7 Mn0．3 O 2,利用 X 射线衍射分析（XRD）表征其结构、扫描电子显微镜（SEM）表征其形貌、X 射线光电子能谱（XPS）表征其价态,最终确定了该材料最佳烧成温度为820℃.研究表明,该温度下合成的 LiNi0．7 Mn0．3 O 2具有典型的α-NaFeO 2型层状结构,颗粒形貌呈类球形且分布均匀；XPS 数据表明,LiNi0．7 Mn0．3 O 2中的 Ni 主要以＋3价形态存在,Mn 主要以＋4价形态存在.室温条件下以0．2 C 倍率在2．75~4．35 V 的电压范围内充放电,首次放电比容量高达188．9 mAh/g,70次循环后容量保持率为95．2％.

英文摘要：

Layered cobalt free nickel rich LiNi0.7 Mn0.3 O 2 cathode material was synthesized via co-precipitation and high temperature sintering in this study.The optimum synthesis condition for LiNi0.7 Mn0.3 O 2 cathode material was investigated in detail.The crystal structure,morphology,valence state of elements and electrochemical performance for LiNi0.7 Mn0.3 O 2 cathode material were characterized and tested by means of powder X-ray dif-fraction （XRD）,scanning electron microscopy （SEM）,X-ray photoelectron spectroscopy （XPS）and galvanos-tatic charge/discharge test separately.The optimum sintering temperature for LiNi0.7 Mn0.3 O 2 cathode material was 820 ℃.The sample synthesized at optimum sintering temperature has a typical α-NaFeO 2 layered structure and homogeneous spherical morphology.XPS results suggest that Ni3 ＋ and Mn4＋ exist mainly in this sample. The initial discharge specific capacity of the material was 188.1 mAh/g at 0.2 C in the voltage range of 2.75-4.35 V,and even after 70 cycles,it still maintains 95.2% of the initial discharge specific capacity.