title: An oxysulfate Fe₂O(SO₄)₂ electrode for sustainable Li-based batteries.
abstract: High-performing Fe-based electrodes for Li-based batteries are eagerly pursued because of the abundance and environmental benignity of iron, with especially great interest in polyanionic compounds because of their flexibility in tuning the Fe(3+)/Fe(2+) redox potential. We report herein the synthesis and structure of a new Fe-based oxysulfate phase, Fe2O(SO4)2, made at low temperature from abundant elements, which electrochemically reacts with nearly 1.6 Li atoms at an average voltage of 3.0 V versus Li(+)/Li, leading to a sustained reversible capacity of ≈125 mAh/g. The Li insertion-deinsertion process, the first ever reported in any oxysulfate, entails complex phase transformations associated with the position of iron within the FeO6 octahedra. This finding opens a new path worth exploring in the quest for new positive electrode materials.
authors.affiliation: FRE 3677 "Chimie du Solide et Energie", Collège de France, 11 Place Marcelin Berthelot, 75231 Paris Cedex 05, France.
authors.forename: Meiling
authors.initials: M
authors.lastname: Sun
authors.forename: Gwenaëlle
authors.initials: G
authors.lastname: Rousse
authors.forename: Artem M
authors.initials: AM
authors.lastname: Abakumov
authors.forename: Gustaaf
authors.initials: G
authors.lastname: Van Tendeloo
authors.forename: Moulay-Tahar
authors.initials: MT
authors.lastname: Sougrati
authors.forename: Matthieu
authors.initials: M
authors.lastname: Courty
authors.forename: Marie-Liesse
authors.initials: ML
authors.lastname: Doublet
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Tarascon