电化学性能的影响
(深圳大学 化学与化工学院，深圳 518060)
摘 要: 以Li2CO3、NiO、Co2O3、MnO2、LiF和SiO2为原料，采用机械力活化固相法制备了Si4+和F－掺杂的锂离子电池正极材料LiNi1/3Co1/3Mn1/3O2。通过X射线衍射(XRD)、扫描电镜(SEM)和电化学性能测试等技术研究了LiNi1/3Co1/3Mn1/3O2的结构特征、形貌及电化学性能等。结果表明：掺杂离子的引入没有改变材料的晶型结构，通过机械力活化后的材料分散更均匀，颗粒也较小，其中Li(Ni1/3Co1/3Mn1/3)0.98Si0.02O1.96F0.04的电化学性能最佳，首次放电比容量达157.5 mA·h/g，充放电循环过程中最高放电比容量为173.3 mA·h/g，循环50次后，容量保持率达96.19%，循环稳定性好。
关键字: LiNi1/3Co1/3Mn1/3O2；机械力活化；掺杂；电化学性能
electrochemical properties of LiNi1/3Co1/3Mn1/3O2
（School of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen 518060, China）
Abstract:The layered LiNi1/3Co1/3Mn1/3O2 cathode materials doped by Si4+ and F− were synthesized by solid state of mechanical activation method using Li2CO3, NiO, Co2O3, MnO2, LiF and SiO2 as the raw materials. The bare sample and doping composites were characterized by X-ray diffraction(XRD), scanning electron microscopy (SEM) and charge-discharge test. The results show that doping does not change the crystal of materials, the doped samples have a smaller grain sizes and uniform distributions, furthermore, the composite Li(Ni1/3Co1/3Mn1/3)0.98Si0.02O1.96F0.04 has a good electrochemical performance, which exhibits initial capacity of 157.5 mA·h/g, and the capacity retains 96.19% after 50 cycles. Through the process of the cycles, the highest discharge specific capacity arrives at 173.3 mA·h/g.
Key words: LiNi1/3Co1/3Mn1/3O2; mechanical activation; doping; electrochemical property
