Abstract :
Electrochemical intercalation of unsolvated lithium ions into pyrographite has been carried out in LiClO4–carbonate electrolyte solution. The pure stage III lithium–graphite intercalation compound has been isolated and characterized by X-ray diffraction studies. The oriented texture of pyrographite has allowed the separated study of the different families of Bragg reflections. The identity period along the c-axis, Ic, is equal to 1040.80 pm corresponding to an intercalation distance dI equal to 374.80 pm. There is no evidence for a 2D structural organization of the intercalated lithium species. The a and b parameters of the graphite sublattice are equal to 246.84 pm corresponding to an in-plane C–C distance of 142.50±0.05 pm. Comparison between experimental data and some theoretical models suggests a ABA/ACA stacking of the graphene layers along the c-axis with a parameter c equal to 2Ic. However, a contribution of a ABA/ABA stacking with c=Ic is also probable.
