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Phosphoric acid and thermal treatments reveal the peculiar role of surface oxygen anions in lithium and manganese-rich layered oxides

He, Jiarong 1; Hua, Weibo 1; Missiul, Aleksandr; Melinte, Georgian 2; Das, Chittaranjan 1; Tayal, Akhil; Bergfeldt, Thomas ORCID iD icon 1; Mangold, Stefan 3; Liu, Xinyang 1; Binder, Joachim R. 1; Knapp, Michael ORCID iD icon 1; Ehrenberg, Helmut 1; Indris, Sylvio ORCID iD icon 1; Schwarz, Björn ORCID iD icon 1; Maibach, Julia 1
1 Karlsruher Institut für Technologie (KIT)
2 Institut für Nanotechnologie (INT), Karlsruher Institut für Technologie (KIT)
3 Institut für Photonenforschung und Synchrotronstrahlung (IPS), Karlsruher Institut für Technologie (KIT)

Abstract:

The interplay between cationic and anionic redox activity during electrochemical cycling makes layered Li-rich oxides appealing cathodes for state-of-the-art lithium-ion batteries. However, it remains challenging as the origin of lattice oxygen activity is not yet fully understood. Here we report on the effects of a lithium-deficient layer in the near-surface region of Co-free Li-rich Li[Li0.2Ni0.2Mn0.6]O-2 (LLNMO) achieved via a phosphoric acid surface treatment. Our results show that oxidized On- (0 < n < 2) species are formed on the surface of H3PO4-treated LLNMO resulting from Li ion deficiency and lattice distortion. The metastable On- could be easily released from the oxygen surface lattice forming O-2 via thermal treatment, accompanied by a surface reconstruction and a layered-to-rock-salt/spinel transition. The presented results demonstrate that the surface lattice structure plays a critical role in the electrochemical performance of LLNMO. This information provides new insights into the oxygen redox in LLNMO and opens up an opportunity for Li-rich cathodes to achieve long cycle life toward a broad range of applications in electrical energy storage devices.


Verlagsausgabe §
DOI: 10.5445/IR/1000126890
Veröffentlicht am 14.04.2021
Originalveröffentlichung
DOI: 10.1039/D0TA07371G
Scopus
Zitationen: 26
Web of Science
Zitationen: 25
Dimensions
Zitationen: 26
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Angewandte Materialien – Energiespeichersysteme (IAM-ESS)
Helmholtz-Institut Ulm (HIU)
Institut für Angewandte Materialien (IAM)
Institut für Nanotechnologie (INT)
Institut für Photonenforschung und Synchrotronstrahlung (IPS)
Karlsruhe Nano Micro Facility (KNMF)
Publikationstyp Zeitschriftenaufsatz
Publikationsdatum 07.01.2021
Sprache Englisch
Identifikator ISSN: 2050-7488, 2050-7496
KITopen-ID: 1000126890
HGF-Programm 37.01.15 (POF III, LK 01) Reaction and Degradation Mechanisms
Weitere HGF-Programme 56.12.11 (POF IV, LK 01) Materials - Quantum, Complex and Functional
Erschienen in Journal of materials chemistry / A
Verlag Royal Society of Chemistry (RSC)
Band 9
Heft 1
Seiten 264–273
Vorab online veröffentlicht am 30.09.2020
Schlagwörter 2020-025-029691, TEM, FIB
Nachgewiesen in Scopus
Dimensions
Web of Science
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