Jump to main content
Jump to site search

Issue 39, 2015
Previous Article Next Article

Structural, electrochemical and magnetic properties of a novel KFeSO4F polymorph

Author affiliations

Abstract

In the quest for sustainable and low-cost positive electrode materials for Li-ion batteries, we discovered, as reported herein, a new low temperature polymorph of KFeSO4F. Contrary to the high temperature phase crystallizing in a KTiOPO4-like structure, this new phase adopts a complex layer-like structure built on FeO4F2 octahedra and SO4 tetrahedra, with potassium cations located in between the layers, as solved using neutron and synchrotron diffraction experiments coupled with electron diffraction. The detailed analysis of the structure reveals an alternation of edge- and corner-shared FeO4F2 octahedra leading to a large monoclinic cell of 1771.774(7) Å3. The potassium atoms are mobile within the structure as deduced by ionic conductivity measurements and confirmed by the bond valence energy landscape approach thus enabling a partial electrochemical removal of K+ and uptake of Li+ at an average potential of 3.7 V vs. Li+/Li0. Finally, neutron diffraction experiments coupled with SQUID measurements reveal a long range antiferromagnetic ordering of the Fe2+ magnetic moments below 22 K with a possible magnetoelectric behavior.

Graphical abstract: Structural, electrochemical and magnetic properties of a novel KFeSO4F polymorph

Back to tab navigation

Supplementary files

Publication details

The article was received on 20 Jul 2015, accepted on 17 Aug 2015 and first published on 17 Aug 2015


Article type: Paper
DOI: 10.1039/C5TA05548B
Citation: J. Mater. Chem. A, 2015,3, 19754-19764
  •   Request permissions

    Structural, electrochemical and magnetic properties of a novel KFeSO4F polymorph

    L. Lander, G. Rousse, A. M. Abakumov, M. Sougrati, G. van Tendeloo and J. Tarascon, J. Mater. Chem. A, 2015, 3, 19754
    DOI: 10.1039/C5TA05548B

Search articles by author

Spotlight

Advertisements