Journal Article

IMPULSE-2022-00029

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Correlating ligand-to-metal charge transfer with voltage hysteresis in a Li-rich rock-salt compound exhibiting anionic redox

Li, B. ; Sougrati, M. T. ; Rousse, G. ; Morozov, A. V. ; Dedryvère, R. ; Iadecola, A. ; Senyshyn, A.MLZ* ; Zhang, L. ; Abakumov, A. M. ; Doublet, M.-L. ; Tarascon, J.-M. (Corresponding author)

2021
Nature Publishing Group London

Please use a persistent id in citations: doi:10.1038/s41557-021-00775-2

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.

Keyword(s): Energy (1st) ; Chemistry (2nd) ; Materials Science (2nd)

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Contributing Institute(s):

1. SPODI (SPODI)
2. STRUCTURE (STRUCTURE)

Experiment(s):

1. SPODI: High resolution powder diffractometer (SR8a)

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Database coverage:
; BIOSIS Previews ; Biological Abstracts ; Chemical Reactions ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF >= 20 ; Index Chemicus ; JCR ; Nationallizenz ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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