Manganese Migration in Li1-xMn2O4 Cathode Materials

Copyright © 2021. Published by Elsevier B.V..

LiMn2O4 has been considered one of the most promising cathode materials for Li-ion batteries due to its thermal stability, abundance, environmental affinity, and the possibility to exchange Li-ions in three-dimensions. However, it still suffers from major problems, such as capacity fading and voltage decay, which has been associated to phase transformations and dissolution of transition metals. In this report, we use scanning transmission electron microscopy, coupled with differential phase contrast (DPC), to better understand the mechanisms behind the structural transformations occurring in LiMn2O4. We use the fact that DPC has the ability to observe simultaneously light and heavy elements, as well as measure projected electric fields and charge distribution at the atomic level. This approach allows us to monitor the migration of very low amounts of Mn to the Li atomic positions, at the surface and subsurface regions, which otherwise is very challenging to observe using other techniques such as HAADF and ABF. These observations not only provide a fundamental understanding of the structure of LiMn2O4 but also reveal DPC as a novel technique to determine local structural changes in materials consisting of heavy and light elements, as well as identify the location of light elements, monitor low concentrations of substitutional species and identify phase transformations.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:225

Enthalten in:

Ultramicroscopy - 225(2021) vom: 15. Juni, Seite 113285

Sprache:

Englisch

Beteiligte Personen:

Calderon V, S [VerfasserIn]
Ribeiro, R M [VerfasserIn]
Ferreira, P J [VerfasserIn]

Links:

Volltext

Themen:

Battery
Cathodes
DPC
Journal Article
Li-ion
STEM

Anmerkungen:

Date Revised 12.05.2021

published: Print-Electronic

Citation Status PubMed-not-MEDLINE

doi:

10.1016/j.ultramic.2021.113285

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM324858523