摘要
用固相法制备球形LiNi0.7Co0.25Al0.05O2粉体,并综合研究该粉体的微观结构和电化学特性.用X射线衍射和透射电子选区衍射分析LiNi0.7Co0.25Al0.05O2的晶体结构.结果表明:LiNi0.7Co0.25Al0.05O2为纯α-NaFeO2型六方晶结构.用扫描电镜观察二次颗粒的形状为球形.从循环伏安扫描实验中发现:掺杂Al元素能够抑制LiNi0.7Co0.3O2在Li+插入-脱出过程中的结构相变,提高材料的循环稳定性.在电压为3.0～4.3 V,充放电倍率为C/5的条件下,LiNi0.7Co0.25Al0.05O2首次放电容量达到161.5 mA＠·h/g,30次循环后放电容量为156.1 mA·h/g,放电容量损失率仅为3.3%.
Spherical LiNi0.7Co0.25Al0.05O2 particles were synthesized by the solid state method. The microstructure and electrochemical characteristics were extensively investigated. The phase structure of LiNi0.7Co0.25Al0.05O2 was identified by X-ray diffraction and transmission electron selected area diffraction. The results show that the crystals are pure hexagonal α-NaFeO2. Scanning electron microscope photographs show that the secondary particles are spherical. Aluminum substitution effectively suppressed phase transitions in the lithium ion intercalation - abjection process by cyclic voltammetry experiment. The discharge capacity of LiNi0.7Co0.25Al0.05O2 is 161.5 mA·h/g in the first cycle and 156. 1 mA·h/g in the 30th cycle, with only 3.3% capacity fading at a charge - discharge rate of C/5 in the potential range of 3.0-4.3 V.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2005年第10期1193-1196,共4页
Journal of The Chinese Ceramic Society
关键词
正极材料
锂离子电池
微观结构
电化学
cathode material
lithium ion battery
microstructure
electrochemistry
