Correlating ligand-to-metal charge transfer with voltage hysteresis in a Li-rich rock-salt compound exhibiting anionic redox - Archive ouverte HAL Access content directly
Journal Articles Nature Chemistry Year : 2021

Correlating ligand-to-metal charge transfer with voltage hysteresis in a Li-rich rock-salt compound exhibiting anionic redox

, , , , (1) , , , , , (2) , (3)
1
2
3

Abstract

Anionic redox is a double-edged sword for Li-ion cathodes because it offers a transformational increase in energy density that is also negated by several detrimental drawbacks to its practical implementation. Among them, voltage hysteresis is the most troublesome because its origin is still unclear and under debate. Herein, we tackle this issue by designing a prototypical Li-rich cation-disordered rock-salt compound Li1.17Ti0.33Fe0.5O2 that shows anionic redox activity and exceptionally large voltage hysteresis while exhibiting a partially reversible Fe migration between octahedral and tetrahedral sites. Through combined in situ and ex situ spectroscopic techniques, we demonstrate the existence of a non-equilibrium (adiabatic) redox pathway enlisting Fe3+/Fe4+ and O redox as opposed to the equilibrium (non-adiabatic) redox pathway involving sole O redox. We further show that the charge transfer from O(2p) lone pair states to Fe(3d) states involving sluggish structural distortion is responsible for voltage hysteresis. This study provides a general understanding of various voltage hysteresis signatures in the large family of Li-rich rock-salt compounds
Fichier principal
Vignette du fichier
s41557-021-00775-2.pdf (3.67 Mo) Télécharger le fichier
Origin : Publisher files allowed on an open archive

Dates and versions

hal-03355093 , version 1 (27-09-2021)

Identifiers

Cite

Biao Li, Moulay Tahar Sougrati, Gwenaëlle Rousse, Anatolii V Morozov, Rémi Dedryvère, et al.. Correlating ligand-to-metal charge transfer with voltage hysteresis in a Li-rich rock-salt compound exhibiting anionic redox. Nature Chemistry, 2021, 13, pp.1070-1080. ⟨10.1038/s41557-021-00775-2⟩. ⟨hal-03355093⟩
54 View
37 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More