Effects of Fluorine Atom Substitution of Graphene Edge Site on the Diffusion of Lithium Ion
Effects of Fluorine Atom Substitution of Graphene Edge Site on the Diffusion of Lithium Ion
复制标题
石墨烯边缘位点氟原子取代对锂离子扩散的影响
DOI：
10.1143/jjap.49.01ah02
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发表时间：
2010
影响因子：
1.5
通讯作者：
H. Kawabata
中科院分区：
文献类型：
--
作者：
H. Tachikawa;T. Iyama;H. Kawabata
直接分子轨道-分子动力学（MO-MD）方法已应用于改性石墨烯表面上Li+离子的扩散过程。由碳、氟和氢原子组成的石墨烯片被用作模型石墨烯（Li+C150H3F27，记为FH-石墨烯）。石墨烯的边缘由氟（F 边缘区域）和氢原子（H 边缘区域）终止。模拟温度选择在 250–350 K 范围内。结果发现，锂离子在表面自由扩散，但离子不会接近表面的 F 边缘区域。这是由于与带正电的碳原子的排斥相互作用，其中 C-F 键被极化为 Cδ+-Fδ-。另一方面，Li+离子接近H边缘区域并从H边缘区域离开。在理论结果的基础上讨论了Li+的扩散机理。
Direct molecular orbital–molecular dynamics (MO–MD) method has been applied to diffusion processes of the Li+ ion on a modified graphene surface. A graphene sheet composed of carbon, fluorine and hydrogen atoms were used as a model graphene (Li+C150H3F27, denoted by FH-graphene). The edges of graphene were terminated by fluorine (F-edge region) and hydrogen atom (H-edge region). Simulation temperatures were chosen in the range 250–350 K. It was found that the lithium ion diffuses freely on the surface, but the ion does not approach the F-edge region of the surface. This is due to the repulsive interaction with a positive charged carbon atom where C–F bond is polarized as Cδ+–Fδ-. On the other hand, the Li+ ion approached to the H-edge region and it exited from the H-edge region. The diffusion mechanism of Li+ was discussed on the basis of theoretical results.