F^-掺杂LiNi_(0.5)Mn_(1.5)O_4材料的制备及性能研究  

Synthesis and Performance of F-doped LiNi_(0.5)Mn_(1.5)O_4 Cathode Material

作　　者：李军[1] 李庆彪[1] 李少芳[1] 朱建新[1] 刘建军[1] 

机构地区：[1]广东工业大学,广东广州510006

出　　处：《稀有金属材料与工程》2017年第2期439-444,共6页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(20672023);广州市科技计划项目(2011Y1-00010);广东省科技计划项目(2015A050502046)

摘　　要：为改善LiNi_(0.5)Mn_(1.5)O_4的倍率性能和循环性能,采用二步固相法制备了F-掺杂的LiNi_(0.5)Mn_(1.5)O_(4-x)F_x(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(LiNi_(0.5)Mn_(1.5)O_(3.9)F_(0.1))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%。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.

关 键 词：LiNi(0.5)Mn(1.5)O4 倍率性能 循环性能 正极材料 F掺杂 

分 类 号：TM912[电气工程—电力电子与电力传动]