摘要
F掺杂可以提高锂离子电池正极材料LiMn2O4的初始容量,但使材料的循环性能变差。其原因是F的掺入降低了Mn的平均价态,Mn3+的量增加,提高了材料的初始容量,但Mn3+量的增加也加剧了Mn的溶解和Jahn Teller畸变,使材料的循环性能变差。F掺杂虽然降低了材料的循环性能,但提高了材料的初始容量,为改善阳离子掺杂方法的不足提供了一条可能的解决途径。
The substitution of F for O increased the initial specific capacity of the cathode material LiMn_2O_4 at the cost of the cycleability .The explanation of this results was that F-dopant decreased the valence of Mn,that is, more Mn^(3+) and less Mn^(4+) existed in the material. The increase of Mn^(3+) elevated the initial specific capacity, however, Mn^(3+) was the original reason of Jahn-Teller effect which caused the poor cycleability of the cathode material by the micro-distortion of the crystal structure. In addition, the increase of Mn^(3+) intensified the amount of dissolution, accordingly, the cyclability was deteriorated. Despite the poor cyclability, the effect of increasing capacity of F-dopant can probably compensate the defect of cation-dopant.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2004年第1期74-76,共3页
Journal of Functional Materials
基金
国家自然科学基金资助项目(59972026)
