Intercalation stage dependence of core electronic excitations in Li-intercalated graphite from inelastic X-ray scattering

G. E. STUTZ; M. OTERO; S.A. CEPPI; C. B. ROBLEDO; G. LUQUE; E. LEIVA; D.E. BARRACO

APPLIED PHYSICS LETTERS

AMER INST PHYSICS

Lugar: New York; Año: 2017 vol. 110

0003-6951

Li and C 1s core-electron excitation spectra of electrochemically prepared stage-II and stage-I lithi-ated graphite were investigated by means of inelastic X-ray scattering spectroscopy. The near-edgestructure is discussed, and the spectral features are interpreted using ab initio calculations. Our resultsconfirm the invariance of the excitation threshold for transitions from C 1s core-states to empty pstates upon Li intercalation for stage-I and show this invariance also occurs for the second stage ofintercalation. A systematic shift of the rexcitation threshold to lower energies with the Li content was observed. The Li core spectra reveal an ionic character of the intercalated Li in stage-I and in stage-II. The present results provide further valuable information for forthcoming in situ studies of lithiation/delithiation processes in graphite anodes by inelastic X-ray scattering spectroscopy.