Low temperature 7Li-NMR investigations on lithium inserted into carbon anodes for rechargeable lithium-ion cells

High-Capacity Reversible Lithium Storage in Defined Microporous Carbon Framework for All Solid-State Lithium Batteries

“…It is consequently moved to lower chemical shifts at room temperature while it splits into two peaks at -30 °C. 22,33,34 The cluster signal for HC pore filling at temperatures below -30 °C can be found at a chemical shift of approximately 180 ppm, which is in good agreement with the chemical shift of the herein depicted 7 Li NMR signal at room temperature. Lithiated HCmicro might lack this shift due to the minor content of ordered graphite domains, which was pointed out earlier by TEM measurements.…”

“…The latter, to the best of our knowledge have not been observed for lithiated carbon electrodes so far. 22,23,[29][30][31][32][33][34] Based on these findings, we propose a lithiation mechanism of HCmicro in the all solidstate system via the reversible formation of extended lithium clusters in the carbon framework.…”

Nano-drilled multiwalled carbon nanotubes: characterizations and application for LIB anode materials

“…Later, it has also been confirmed by low temperature Li-NMR that lithium stored in the small space, like cavities and voids, is in a metallic cluster form. 37,38 Considering that carbon materials may also contain functional groups on their edges and defects, 8,9 another idea based on the redox reaction of Li and functional groups has been introduced. A reversible reduction and oxidation reaction (C]O + Li + + e À 4 C-OLi) between lithium ions and surface functionalities, with the peak of 3.0 V vs. Li + /Li, has been reported in the study of functional groups for high performance batteries.…”

Metallic properties of Li-intercalated carbon nanotubes investigated by NMR

“…Such Knight shifts are typical for a limited charge transfer of the 2s electron of Li stored in a dense form in nanoporosities. 26 According to recent calculations, 24 the outside-Li adsorption is energetically more favorable than the Li inside the SWNT. In particular, the curvature of the graphene layer in SWNT and the presence of high reactive dangling bonds localized on defects tend to enhance the adsorption capabilities.…”