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...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％.展开更多
Advanced uniform LiNi0.7Co0.15Mn0.15O2 microspheres were successfully synthesized and examined as cathode materials for lithium-ion batteries. The structure,morphology, and electrochemical performance of LiNi0.7-Co0.1...Advanced uniform LiNi0.7Co0.15Mn0.15O2 microspheres were successfully synthesized and examined as cathode materials for lithium-ion batteries. The structure,morphology, and electrochemical performance of LiNi0.7-Co0.15Mn0.15O2 calcined at different temperatures ranging from 650 to 900 °C were systematically investigated. The XRD results show that the material has a well-ordered layered structure with small amount of cation mixing. A distinct spherical morphology of the obtained powders prepared at different temperatures can be seen from the SEM images. The as-synthesized LiNi0.7Co0.15Mn0.15O2 powders have a very high-tap density of about 2.37 g·cm^-3. Among all the samples,the sample calcined at 750 °C exhibits the best electrochemical performance with an initial discharge capacity of185.2 mAh·g^-1（3.0–4.3 V, 0.2C rate） and capacity retention〉94.77 %after50cycles.Moreover,thismaterialshowshighspecific capacity and good cycling stability. The LiNi0.7-Co0.15Mn0.15O2 microspheres with high-specific capacity and high-tap density are promising to use as cathode materials for next-generation high-energy-density lithium-ion batteries.展开更多
文摘采用共沉淀-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％.
基金financially supported by the National Natural Science Foundation of China (No. 21001117)the National Science Foundation for Post-Doctoral Scientists of China (No. 2011M501286)
文摘Advanced uniform LiNi0.7Co0.15Mn0.15O2 microspheres were successfully synthesized and examined as cathode materials for lithium-ion batteries. The structure,morphology, and electrochemical performance of LiNi0.7-Co0.15Mn0.15O2 calcined at different temperatures ranging from 650 to 900 °C were systematically investigated. The XRD results show that the material has a well-ordered layered structure with small amount of cation mixing. A distinct spherical morphology of the obtained powders prepared at different temperatures can be seen from the SEM images. The as-synthesized LiNi0.7Co0.15Mn0.15O2 powders have a very high-tap density of about 2.37 g·cm^-3. Among all the samples,the sample calcined at 750 °C exhibits the best electrochemical performance with an initial discharge capacity of185.2 mAh·g^-1（3.0–4.3 V, 0.2C rate） and capacity retention〉94.77 %after50cycles.Moreover,thismaterialshowshighspecific capacity and good cycling stability. The LiNi0.7-Co0.15Mn0.15O2 microspheres with high-specific capacity and high-tap density are promising to use as cathode materials for next-generation high-energy-density lithium-ion batteries.
