Fine structure and chemical shifts in nonresonant inelastic x-ray scattering from Li-intercalated graphite

The authors report measurements of hard x-ray nonresonant inelastic x-ray scattering (IXS) from the Li and C $1s$ electrons of fully staged $LiC6$ Li-intercalated graphite prepared by both chemical and electrochemical methods. They find that the Li $1s$ orbital shifts to higher energies relative to Li metal. Relative to graphite, the C $1s$ IXS for $LiC6$ shows a shift for the $σ$-orbital threshold to lower energies, but no shift for the $π*$ resonance. The findings provide bulk-sensitive evidence for substantial charge transfer from the Li intercalant to the carbon host and establish important groundwork for future in situ electrochemical studies.