摘要
采用基于泛函理论的第一性原理,应用超软赝势平面波法对LiMn2O4以及Ni 2+掺杂的LiMn2O4的能带结构、态密度进行研究。理论计算表明:LiMn2O4是导体材料,Mn位掺杂Ni 2+可以减小LiMn2O4的能带间隙,缩短Mn-O键长,降低Li-O键能,提高LiMn2O4的电子电导率以及锂离子的扩散速率。电子态密度分析发现:由于Ni-3d轨道的诱导作用,出现了新的O-2p轨道,Li脱出时获得的电子主要是由费米能级附近O-2p能带提供,因此掺杂Ni 2+能提高LiMn2O4的导电性能。相关实验结果表明,掺杂Ni 2+的LiMn2O4具有优良的电化学性能,与理论计算结果非常符合。
The electronic properties of cathode material LiMn204 and LiNi0.5 Mnl. 5 04 formed by doped Ni2＋ in LiMn204 were calculated using the first-principles based on functional theory. Theoretical calculations show that, LiMn2 04 is a conductor material; LiMn2 04 doped Ni2 ＋ ions by the Mn site can reduce band gap, shorten Mn-O bond length, and reduce Li-O bond energy, thus improving electronic conductivity and the diffusion rate of lithium ions of LiMn2 04. The electronic density of states analysis indicated that for the induce of Ni-3d orbit, resulting in a new O-2p orbital, while the electrons obtained when the Li getting off were provided by the O-2p orbital near the Fermi level, so LiMn2 04 doped Ni2＋ was able to improve the performance of conductivity of LiMn2 04 materials. The related experi- mental results show that LiMn2 04 doped Ni2＋ has excellent electrochemical performance very much, which is consistent in line with the theoretical calculation results.
出处
《材料导报》
EI
CAS
CSCD
北大核心
2014年第4期149-152,共4页
Materials Reports
基金
中央高校基本科研业务费专项资金(2013DXS02)
关键词
第一性原理
锂离子电池
能带结构
密度泛函理论
first-principles, lithium-ion batteries, band structure, density functional theory
