合成条件对LiCo_(0.2)Ni_(0.8)O_2正极材料结构与性能的影响  

THE EFFECT OF DIFFERENT SYNTHESIS CONDITION ON THE STRUCTURE AND PROPERTIES OF LiCo_(0.2)Ni_(0.8)O_2CATHODE MATERIALS

作　　者：魏进平[1] 王晓宇[1] 孙欣[1] 翟金铃[1] 阎杰[1] 卞锡奎[1] 

机构地区：[1]南开大学新能源材料化学研究所,天津300071

出　　处：《南开大学学报（自然科学版）》2004年第3期66-72,共7页Acta Scientiarum Naturalium Universitatis Nankaiensis

基　　金：国家重点基础研究发展计划资助项目(2002CB211800)

摘　　要：对LiCo0.2Ni0.8O2正极材料的合成条件进行了研究.实验表明,该材料在空气气氛中合适的合成温度为700℃,反应时间为12 h,在该反应条件下正极材料晶体结构有序化程度及晶体结构完善性均比较理想,其电化学性能较好.在通氧条件下制备得到的正极材料LiCo0.2Ni0.8O2具有良好的电化学性能,其初始放电容量175mAh／g,经过50次充放电循环后放电容量为153 mAh／g,而且正极材料中锂离子的扩散系数有了较大的增加,这有利于正极材料中锂离子的迁入和脱嵌,因此LiCo0.2Ni0.8O2正极材料具有良好的充放电循环性能.LiCo0.2Ni0.8O2 cathode materials were synthesized by a conventional solid-state method. The products were characterized by XRD, galvanostatic cycling, electrochemical impedance spectroscopy and potential step chronoamperometry. The LiCo0.2 Ni0.8 O2 cathode material, which was fired at 700 ℃ for 12 h in flowing air has a better indicator of hexagonal ordering of the system and lower degree of cation mixing and its electrochemical properties is improved. For the LiCo0.2 Ni0.8 O2 cathode material fired in flowing oxygen, the discharge capacities in the 1st and 50 th cycles were 175 mAh/g and 153 mAh/g with charge retention of 87% and the chemical diffusion coefficient of Li-ion has greatly improved.

关 键 词：锂离子电池 正极材料 LiC0.2Ni0.8O2 合成条件 

分 类 号：TM911[电气工程—电力电子与电力传动]