Local structure and redox energies of lithium phosphates with olivine- and Nasicon-like structures

A. Ait Salah (1) , P. Jozwiak , J. Garbarczyk , K. Benkhouja , K. Zaghib , F. Gendron (1) , C. Julien (1)

1 LMDH - Laboratoire des Milieux Désordonnés et Hétérogènes

An experimental relationship between local structure and electrochemical properties is established for lithium metal phosphates LiMePO4 (Me = Fe, Co, Mn), LiFeP2O7 and Li3Fe2(PO4)3 which crystallise with either the olivine-like or the Nasicon-like structure. Structural features of several lithium metal phosphates are investigated by a local probe such as the FTIR spectroscopy in order to explain the influence of either PO43− or P2O74− covalent bonds on redox energies. The local cationic arrangement is also discussed with the aid of a molecular vibration model to figure out the strong covalent bonds within a PO43− complex for glassy Nasicon compounds.

Mots clés: Lithium metal phosphates; Li-ion batteries; FTIR spectroscopy; Phospho-olivines; Diphosphates; Nasicon

A. Ait Salah, P. Jozwiak, J. Garbarczyk, K. Benkhouja, K. Zaghib, et al.. Local structure and redox energies of lithium phosphates with olivine- and Nasicon-like structures. Journal of Power Sources, 2004, 140 (2), pp.370. ⟨10.1016/j.jpowsour.2004.08.029⟩. ⟨hal-00017240⟩