Critical electronic structures controlling phase transitions induced by lithium ion intercalation in molybdenum disulphide  

作　　者：CHEN XiaoBo CHEN ZhenLian LI Jun 

机构地区：[1]Ningbo Institute of Material Technology & Engineering, Chinese Academy of Sciences

出　　处：《Chinese Science Bulletin》2013年第14期1632-1641,共10页

基　　金：supported by the Ningbo Key Innovation Team and the Ningbo Natural Science Foundation (2011B82005, 2012A610098);the Natural Science Foundation of Zhejiang Province (LQ12A04004);the National Natural Science Foundation of China (11174301);the National Basic Research Program of China (2012CB722700, SS2013AA050901);X.Chen appreciates supports by the Postdoctoral Foundation of China(2012M510156)

摘　　要：We report on first-principles studies of lithium-intercalation-induced structural phase transitions in molybdenum disulphide (MoS2 ), a promising material for energy storage in lithium ion batteries. It is demonstrated that the inversion-symmetry-related Mo-S p-d covalence interaction and the anisotropy of d-band hybridization are the critical factors influencing the structural phase transitions upon Li ion intercalation. Li ion intercalation in 2H-MoS2 leads to two competing effects, i.e. the 2H-to-1T transition due to the weakening of Mo-S p-d interaction and the D 6h crystal field, and the charge-density-wave transition due to the Peierls instability in Li-intercalated 2H phase. The stabilization of charge density wave in Li-intercalated MoS2 originates from the enhanced electron correlation due to nearest-neighbor Mo-Mo d-d covalence interaction, conforming to the extended Hubbard model. The magnitude of charge density wave is affected by Mo-S p-d covalence interaction and the anisotropy of d-band hybridization. In 1T phase of Li-intercalated MoS2 , the strong anisotropy of d-band hybridization contributes to the strong Fermi surface nesting while the d-band nonbonding with S-p facilities effective electron injection.We report on first-principles studies of lithium-intercalation-induced structural phase transitions in molybdenum disulphide （MoS2）, a promising material for energy storage in lithium ion batteries. It is demonstrated that the inversion-symmetry-related Mo-S p-d covalence interaction and the anisotropy of d-band hybridization are the critical factors influencing the structural phase transitions upon Li ion intercalation. Li ion intercalation in 2H-MoS2 leads to two competing effects, i.e. the 2H-to-lT transition due to the weakening of Mo-S p-d interaction and the D6h crystal field, and the charge-density-wave transition due to the Peierls instability in Li-intercalated 2H phase. The stabilization of charge density wave in Li-intercalated MoS2 originates from the en- hanced electron correlation due to nearest-neighbor Mo-Mo d-d covalence interaction, conforming to the extended Hubbard mod- el. The magnitude of charge density wave is affected by Mo-S p-d covalence interaction and the anisotropy of d-band hybridiza- tion. In 1T phase of Li-intercalated MoS2, the strong anisotropy of d-band hybridization contributes to the strong Fermi surface nesting while the d-band nonbonding with S-p facilities effective electron injection.

关 键 词：锂离子电池 二硫化钼 结构相变 电子控制 HUBBARD模型 电荷密度波 诱导 各向异性 

分 类 号：TM912[电气工程—电力电子与电力传动]