Sodium intercalation in the phosphosulfate cathode NaFe2(PO4)(SO4)2

Hamdi Yahia, Rachid Essehli, Md. Ruhul Amin, Khalid Boulahya, Toyoki Okumura, Ilias Belharouak

Research output: Contribution to journalArticle

9 Citations (Scopus)


The compound NaFe2(PO4)(SO4)2 is successfully synthesized via a solid state reaction route and its crystal structure is determined using powder X-ray diffraction data. NaFe2(PO4)(SO4)2 phase is also characterized by cyclic voltammetry, galvanostatic cycling and electrochemical impedance spectroscopy. NaFe2(PO4)(SO4)2 crystallizes with the well-known NASICON-type structure. SAED and HRTEM experiments confirm the structural model, and no ordering between the PO4 −3 and SO4 −2 polyanions is detected. The electrochemical tests indicate that NaFe2(PO4)(SO4)2 is a 3 V sodium intercalating cathode. The electrical conductivity is relatively low (2.2 × 10−6 Scm−1 at 200 °C) and the obtained activation energy is ∼0.60eV. The GITT experiments indicate that the diffusivity values are in the range of 10−11-10−12 cm2/s within the measured sodium concentrations.

Original languageEnglish
Pages (from-to)144-151
Number of pages8
JournalJournal of Power Sources
Publication statusPublished - 1 Apr 2018



  • Conductivity
  • Diffusivity
  • Nasicon
  • Phosphosulfate
  • Sodium batteries

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Energy Engineering and Power Technology
  • Physical and Theoretical Chemistry
  • Electrical and Electronic Engineering

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