F掺杂对LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2的电化学性能的影响

Effects of F doping on electrochemical performance of LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2

以醋酸锂、乙酸镍、乙酸锰、乙酸钴和氟化锂为原料,采用高温固相法制备正极材料LiNi1/3Co1/3Mn1/3O2-xFx,采用X射线衍射仪（XRD）和扫描电子显微镜（SEM）对材料的结构和形貌进行了表征,用恒电流充放电测试系统测试材料的电化学性能和循环性能。结果表明：适当的F掺杂可以提高LiNi1/3Co1/3Mn1/3O2正极材料的晶体结构稳定性,使其具有良好的电化学性能。合成的LiNi1/3Co1/3Mn1/3O1.96F0.04样品具有典型的空间群为R-3m的六方层状α-NaFeO2结构,且结构完整,阳离子混排程度较低。颗粒大小分布比较均匀,粒径大小在250-660nm。该样品在0.1C放电倍率和2.6-4.6V电压范围的首次放电比容量为181.1mAh/g,并表现出良好的循环性能。

LiNi1/3Co1/3Mn1/3O2-xFxwas synthesized from LiF, CH3COOLi·2H2O, Ni（CH3COO）2·4 H2 O, Co（CH3COO）2·4H2O and Mn（CH3COO）2·4H2O by high temperature solid method and the physical and electrochemical properties of the material were characterized by X-ray diffraction（XRD）, scanning electron microscope（SEM） and galvanostatic charge-discharge test. The results show that adding proper content of Li F can enhance the structural stability of LiNi1/3Co1/3Mn1/3O2 and make it have excellent electrochemical performance. The sample of LiNi1/3Co1/3Mn1/3O1.96F0.04 had the typical structure of hexagonal α-Na Fe O2 type. Crystal structure was complete and cationic degree of order was best. The size of the particle was in the range of 250~660 nm. Electrochemical test indicated the first discharge capacities of the sample was 181.1 m Ah/g in the voltage range of 2.6~4.6 V and at 0.1 C. And its cycling performance was good.