NaSICON NaFe2PO4(SO4)2 Revisited: Insights into the Crystal Structure and Electrochemical Performance
Year: 2025
Type: article
Abstract: With the aim to meet the needs for positive electrode materials for Na-ion batteries, based on abundant elements, synthesis routes using two different Fe 3+ precursors were explored for the preparation of a pure mixed phosphate-sulfate NaSICON-type compound, NaFe 2 3+ PO 4 (SO 4 ) 2 (NFPS). Interestingly, a structural model described in the R -3 space group is found from careful analysis of X-ray, neutron, and electron diffraction. Atoms P and S (and thus, PO 4 and SO 4 anionic groups) are statistically distributed within the polyanionic framework, with a splitting of the conventional Na2 3 b site into two positions 3 a and 18 f . Na-half cells with NFPS as a positive electrode material delivered 126 mAh/g, nearly the full theoretical capacity, at a cycling rate of D/30–C/30 (i.e., the exchange of 2 Na + in 30 h).
Source: ACS Applied Energy Materials
Institutions: Centre National de la Recherche Scientifique, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Laboratoire d’Innovation pour les Technologies des Énergies Nouvelles et les nanomatériaux, CEA Grenoble, Réseau sur le Stockage Electrochimique de l'énergie, Alistore, Institut de Chimie de la Matière Condensée de Bordeaux, Laboratoire de Réactivité et Chimie des Solides, Institut Polytechnique de Bordeaux, Université de Picardie Jules Verne, Université Grenoble Alpes, Institut Laue-Langevin, Institut Universitaire de France
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4414173215