Thermodynamics and crystal structure anomalies in lithium-intercalated graphite

Rachid Yazami (1) , Yvan F. Reynier

1 CALTECH - California Institute of Technology

We found anomalous behaviors during lithium electrochemical intercalation into graphite in the entropy curve and the crystal structure, especially, during the stages from 2 to 1 transition at x = 0.5 in Li_xC₆. The entropy first decreases monotonously, then re-increased sharply at the transition. The average interlayer spacing displays a hysteresis during intercalation and de-intercalation and departs from linearity. The results are discussed in relation with a contribution of the vibrational entropy and possible occurrence of intermediary phase(s) between the two lithium-rich intercalation stages.

Mots clés: Graphite; Lithium; Entropy; Stage; Phase transition

Domaines: Matériaux

Rachid Yazami, Yvan F. Reynier. Thermodynamics and crystal structure anomalies in lithium-intercalated graphite. Journal of Power Sources, 2006, 153 (2), pp. 312-318. ⟨10.1016/j.jpowsour.2005.05.087⟩. ⟨hal-00386397⟩