Nikolaev Institute of Inorganic Chemistry SB RAS, 3 Acad. Lavrentiev Avenue, Novosibirsk 630090, Russia.
Phys Chem Chem Phys. 2018 Sep 12;20(35):22592-22599. doi: 10.1039/c8cp01510d.
Investigation of carbon/lithium interfaces is of great importance for elaboration of energy storage devices. Here, the effect of vacuum thermal deposition of lithium on single-walled carbon nanotubes (SWCNTs) is investigated by in situ X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure spectroscopy. From the XPS data, the composition of lithiated sample is LiC24. That corresponds to the presence of two types of carbon atoms on the SWCNT surface, namely, those located closely and far away from the adsorbed lithium. Quantum-chemical modeling of XPS valence-band spectra and calculation of atomic charges and molecular electrostatic potential map found that the former type of carbon atoms is in strong positive electric field created by lithium, whereas the Li-free SWCNT areas are charged negatively. An alternation of areas of positive potential and negative potential on the surface of partially lithiated SWCNTs can significantly affect processes in an electrochemical cell.
研究碳/锂界面对于阐述储能设备具有重要意义。在这里，通过原位 X 射线光电子能谱（XPS）和近边 X 射线吸收精细结构光谱研究了真空热沉积锂对单壁碳纳米管（SWCNTs）的影响。从 XPS 数据可以看出，锂化样品的组成为 LiC24。这对应于 SWCNT 表面上两种类型的碳原子，即吸附锂附近和远离吸附锂的碳原子。XPS 价带谱的量子化学建模和原子电荷以及分子静电势图的计算表明，前一种类型的碳原子处于由锂产生的强正电场中，而无锂的 SWCNT 区域则带负电荷。部分锂化 SWCNTs 表面上正电势和负电势区域的交替会显著影响电化学电池中的过程。
