A 3.90 V iron-based fluorosulphate material for lithium-ion batteries crystallizing in the triplite structure

P Barpanda; M Ati; B C Melot; G Rousse; J-N Chotard; M-L Doublet; M T Sougrati; S A Corr; J-C Jumas; J-M Tarascon

doi:10.1038/nmat3093

A 3.90 V iron-based fluorosulphate material for lithium-ion batteries crystallizing in the triplite structure

Nat Mater. 2011 Oct;10(10):772-9. doi: 10.1038/nmat3093.

Authors

P Barpanda¹, M Ati, B C Melot, G Rousse, J-N Chotard, M-L Doublet, M T Sougrati, S A Corr, J-C Jumas, J-M Tarascon

Affiliation

¹ Laboratoire de Réactivité et Chimie des Solides, CNRS UMR 6007, Université de Picardie Jules Verne, 80039 Amiens, France.

PMID: 21857675
DOI: 10.1038/nmat3093

Abstract

Li-ion batteries have empowered consumer electronics and are now seen as the best choice to propel forward the development of eco-friendly (hybrid) electric vehicles. To enhance the energy density, an intensive search has been made for new polyanionic compounds that have a higher potential for the Fe²⁺/Fe³⁺ redox couple. Herein we push this potential to 3.90 V in a new polyanionic material that crystallizes in the triplite structure by substituting as little as 5 atomic per cent of Mn for Fe in Li(Fe(1-δ)Mn(δ))SO₄F. Not only is this the highest voltage reported so far for the Fe²⁺/Fe³⁺ redox couple, exceeding that of LiFePO₄ by 450 mV, but this new triplite phase is capable of reversibly releasing and reinserting 0.7-0.8 Li ions with a volume change of 0.6% (compared with 7 and 10% for LiFePO₄ and LiFeSO₄F respectively), to give a capacity of ~125 mA h g⁻¹.