中文摘要：

为改善LiNi0.5Mn1.5O4的倍率性能和循环性能,采用二步固相法制备了F-掺杂的LiNi0.5Mn1.5O4-xFx（x=0,0.05,0.1,015,0.2）正极材料,讨论了不同F掺杂量对材料性能的影响。X射线衍射、扫描电镜结果表明,掺杂和未掺杂的正极材料都为单一的尖晶石结构,粒度分布均匀。充放电测试、循环伏安和交流阻抗测试结果表明：当F的掺杂量为x=0.1时（LiNi0.5Mn1.5O3.9F0.1）正极材料的性能最好,0.1,0.5,1,2及5C倍率的首次放电比容量依次为129.07,123.59,118.49,114.49和92.57 mAh/g。1C倍率下循环30次,容量保持率仍为98.84%。

英文摘要：

To improve the electrochemical rate capability and cyclic performance of LiNi0.5Mn1.5O4,a two step solid-state reaction was adopted to synthesize LiNi0.5Mn1.5O4-xFx（x=0,0.05,0.1,0.15,0.2） cathode materials.The effect of F-doping on the performance of LiNi0.5Mn1.5O4 was investigated.X-ray diffraction,scanning electron microscopy,the charging-discharging test,cyclic voltammetry tests,and electrochemical impedance spectroscopy were employed to study their properties.The results show that both the doped and the un-doped cathode materials are cubic spinel structure with clearly defined shape and uniform particle size distribution.The cathode material LiNi0.5Mn1.5O3.9F0.1 presents the best electrochemistry performance;at the charge-discharge rate of 0.1,0.5,1,2 and 5 C,its initial discharge specific capacity is 129.07,123.59,118.49,114.49 and 92.57 mAh/g,respectively.When cycled at 1C rate,LiNio.5Mn1.5O3.9F01 can retain 98.84%of its initial capacity after 30 cycles.