摘要
采用控制结晶工艺合成了球形Mn3O4,通过在球形Mn3O4的表面包覆Al(OH)3,然后与LiOH一起混合焙烧制备了表面掺杂Al的尖晶石LiMn2O4。采用SEM,XRD,EDS以及电池系统测试等方法,研究了所制备材料的结构和性能。SEM分析表明:表面掺杂后,Al(OH)3均匀地包覆在颗粒表面。XRD和EDS分析表明:焙烧后,Al元素占据了Mn的位置,且颗粒表面的Al含量高于其总体的平均含量,说明Al只是在表面富集,即表面掺杂。电池测试表明:表面掺杂后,尖晶石LiMn2O4的初始充放电容量有所下降,但在高温55℃下的循环性能有显著的提高,表面掺杂6%Al的尖晶石LiMn2O450次循环的容量保持率从68.3%提高到79.0%。说明以Al3+作为掺杂离子通过表面掺杂来改善LiMn2O4的高温循环性能是有效的。
The spherical Mn3O4 was prepared by a controlled crystallization process, and the spherical spinel LiMn2O4 was produced by the following procedure： the surface of the spherical Mn3O4 was coated with Al（OH）3, then mixed with LiOH and sintered. The structure and performances of the above material were studied by SEM, XRD, EDS etc. SEM analysis showed that the Al（OH）3 was uniformly coated on the surface of spherical Mn3O4. XRD and EDS analysis＇s indicated that the Al^3＋ ions occupied the sites of manganese and Al content of its surface was higher than the average value, indicating that the aluminum was only enriched on the surface of the particles, e.g. the surface doping. Specific capacity of spherical LiMn2O4 decreased after the doping, but its cycle ability at 55℃ was improved. Its capacity retention for the spinel LiMn2O4 doped with 6%Al at 50^th cycle at 55℃ increased from 68.3% to 79.0%. It means that the surface doping of aluminum is an effective way to improve the elevated temperature performances of spherical spinel LiMn2O4.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2006年第12期1987-1990,共4页
Rare Metal Materials and Engineering
关键词
球形尖晶石锰酸锂
表面掺杂
铝
高温性能
spherical spinel LiMn2O4
surface doping
aluminum
elevated temperature
