Complementary Ion Beam Analysis and Raman Studies for Investigation of the Carbon Coating Impact on Li Insertion/Deinsertion Process at LiFePO$_4$/C Electrodes

Suzy Surblé (1) , Aurelien Habrioux (1) , Cyril Paireau (1) , Pascal Berger (1) , Hicham Khodja (1) , Delphine D. Neff (2, 3) , Dominique Gosset (4) , Sophie Mailley (5) , Sébastien S. Patoux (5)

1 LEEL - UMR 3685 - Laboratoire d'Etudes des Eléments Légers
2 LAPA - UMR 3685 - Laboratoire Archéomatériaux et Prévision de l'Altération
3 IRAMAT - LMC - IRAMAT - Laboratoire Métallurgies et Cultures
4 SRMA - Service des Recherches Métallurgiques Appliquées
5 LITEN - Laboratoire d'Innovation pour les Technologies des Energies Nouvelles et les nanomatériaux

Electrode materials were prepared using two commercial C-LiFePO$_4$ powders (called hereafter LFP-A and LFP-B). The nature and the thickness of carbon coating have been characterized by Raman spectroscopy and Transmission Electron Microscopy. The carbon coating of the LFP-B is more graphitized than LFP-A, which appears amorphous. The lithium distribution of these electrodes is investigated using ion beam techniques as a function of its state of charge (SOC). The nuclear microanalyses reveal the presence of different dopings in the active materials (Ti or V). A layer richer in carbon (in addition to the composite electrode) is systematically observed on LFP-A pristine and cycled electrodes. In both materials, immobilization of lithium is visible. Higher content of lithium was observed for the LFP-B electrode.

Domains: Material chemistry; Catalysis

Suzy Surblé, Aurelien Habrioux, Cyril Paireau, Pascal Berger, Hicham Khodja, et al.. Complementary Ion Beam Analysis and Raman Studies for Investigation of the Carbon Coating Impact on Li Insertion/Deinsertion Process at LiFePO$_4$/C Electrodes. Journal of The Electrochemical Society, 2017, 164 (14), pp.A3538-A3544. ⟨10.1149/2.0471714jes⟩. ⟨cea-01636441⟩