Study of a Layered Iron(III) Phosphate Phase Na3Fe3 ( PO4 ) 4 Used as Positive Electrode in Lithium Batteries

Abstract

The layered phase prepared by solid-state reaction was studied as positive electrode in lithium batteries. Up to 1.9 ions/f.u. could be intercalated, and only 1.7 ions could be extracted between 4.5 and 2 V vs with an average voltage of around . 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, 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.