Study of layered iron(III) phosphate phase Na3Fe3(PO4)4 used a positive electrode in lithium batteries

Khiem Trad (1, 2) , Dany Carlier-Larregaray (1) , Alain Wattiaux (1) , Mongi Ben Amara (2) , Claude Delmas (1)

1 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
2 Matériaux Inorganiques

The layered Na₃Fe₃(PO₄)₄ phase prepared by solid-state reaction was studied as positive electrode in lithium batteries. Up to 1.9 Li⁺ ions/f.u. could be intercalated, and only 1.7 Li⁺ ions could be extracted between 4.5 and 2 V vs Li⁺/Li with an average voltage of around ~2.8  V. In situ and ex situ X-ray diffraction data and Mössbauer spectroscopy measurements indicate that the intercalation/deintercalation process occurs through a solid solution process and is reversible. To improve its electrochemical performances, Na₃Fe₃(PO₄)₄ was also prepared via a hydrothermal method that leads to a significant particle size reduction. However, no clear improvements of the cycling performances were observed using this material as positive electrode in sodium and lithium batteries.

Mots clés: Electrodes; Intercalation compounds; Mossbauer spectroscopy; Secondary cells; Sodium compounds; Solid solutions; X-ray diffraction

Domaines: Matériaux

Khiem Trad, Dany Carlier-Larregaray, Alain Wattiaux, Mongi Ben Amara, Claude Delmas. Study of layered iron(III) phosphate phase Na3Fe3(PO4)4 used a positive electrode in lithium batteries. Journal of The Electrochemical Society, 2010, 157 (8), pp.A947-A952. ⟨10.1149/1.3442365⟩. ⟨hal-00494474⟩