Electrochemical Intercalation of Sodium Ions into Thermally Reduced Graphite Oxide

Abstract

The structure of carbon obtained from the thermal reduction of graphite oxide at 900°C after electrochemical storage sodium ions was investigated. X-ray diffraction measurement of the carbon sample after charged to various potentials indicated that sodium ions are stored between the layers of carbon below 0.3 V vs. Na/Na + though the interlayer spacing of it was similar to that of graphite. The lower LUMO energy as revealed from the broad π* peak in the region of CK observed in soft X-ray absorption measurement was responsible for the intercalation of a large amount of sodium ions into the present carbon material.

Elucidating the Origin of the Low Anion Intercalation Potential of Graphene-like Graphite: A DFT Study

“…As shown on the right side of Table , GLG obtained at 700 °C (GLG700) had an interlayer distance of 0.338–0.340 nm and an oxygen content of 5.0%, as experimentally analyzed in our previous study. , These values are intermediate between K-GLG, L-GLG, and E-GLG (small), which have low oxygen content and relatively small interlayer distance, and E-GLG (large), which has high oxygen content and relatively large interlayer distance. Our previous experimental results suggested that there is not a single type of oxygen-containing functional group inside GLG, but rather that all of these groups are present. ,, Therefore, assuming an average structure for these models, their oxygen content and interlayer distance would be roughly close to the experimental values for GLG700, and the present calculations could explain the experimental values.…”

“…Our previous experimental results suggested that there is not a single type of oxygen-containing functional group inside GLG, but rather that all of these groups are present. 22,23,25 Therefore, assuming an average structure for these models, their oxygen content and interlayer distance would be roughly close to the experimental values for GLG700, and the present calculations could explain the experimental values.…”

“…These oxygen-containing functional groups are previously suggested by our studies to be present inside GLG. 22,23,25 Two models with different amounts of ether were prepared to investigate the effect of the amount of ether introduced. Each model is abbreviated as K-GLG, L-GLG, E-GLG (small), and E-GLG (large), as shown in the caption of Figure 1.…”

“…In this respect, we have studied a carbon material obtained by heat treatment of graphite oxide, named graphene-like graphite (GLG), − as a DIB cathode active material. , GLG contains oxygen-containing functional groups inside and its interlayer distance is slightly larger than that of graphite . We have previously reported that GLG exhibits a large PF 6 – intercalation/deintercalation capacity of 137 mAh g –1 , and an even larger reversible capacity of 150 mAh g –1 for FSA intercalation/deintercalation .…”

Sodium‐Coordinated Polymeric Phthalocyanines as Stable High‐Capacity Organic Anodes for Sodium‐Ion Batteries

“…The 1 H NMR spectra of both O-Pn and S-Pn dimers show the corresponding proton peaks at the aromatic region and aliphatic region. Also, 13 C{ 1 H} NMR spectra identify the corresponding carbon peaks, supporting successful preparation and purification of Pn dimers. 1-Pentanol was used as the solvent to dissolve Na metal, and the resulting NaOC 5 H 11 suspension was used to prepare S-and O-pNaPcs from their respective Pn dimers.…”