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ID 60290
Author
Gotoh, Kazuma Graduate School of Natural Science & Technology, Okayama University Kaken ID researchmap
Yamakami, Tomu Graduate School of Natural Science & Technology, Okayama University
Nishimura, Ishin Graduate School of Natural Science & Technology, Okayama University
Kometani, Hina Graduate School of Natural Science & Technology, Okayama University
Ando, Hideka Graduate School of Natural Science & Technology, Okayama University
Hashi, Kenjiro National Institute for Materials Science
Shimizu, Tadashi National Institute for Materials Science
Ishida, Hiroyuki Graduate School of Natural Science & Technology, Okayama University Kaken ID publons researchmap
Abstract
A precise understanding of the mechanism for metal (Li and Na) plating on negative electrodes that occurs with overcharging is critical to managing the safety of lithium- and sodium-ion batteries. In this work, an in-depth investigation of the overlithiation/oversodiation and subsequent delithiation/desodiation of graphite and hard carbon electrodes in the first cycle was conducted using operando7Li/23Na solid-state NMR. In the 7Li NMR spectra of half cells of carbon electrodes and metal counter electrodes, three types of signals corresponding to Li dendrites that formed on the surface of graphite, hard carbon, and the counter electrode were distinguished from the signal of Li metal foil of the counter electrode by applying an appropriate orientation of the testing cell. For graphite overlithiation, the deposition of Li dendrites started immediately or soon after the minimum electric potential in the lithiation curve. In contrast, the deposition of Li dendrites in hard carbon started after the end of quasimetallic lithium formation for overlithiation at rates below 3.0C. Similar behaviour was also observed for the oversodiation of hard carbon. The formation of quasimetallic Li or Na in the pores of hard carbon serves as a buffer for the metal plating that occurs with overcharging of the batteries. Furthermore, some of the deposited Li/Na dendrites contribute to reversible capacities. A mechanism for the inhomogeneous disappearance of quasimetallic Li during delithiation of hard carbon is also proposed.
Note
This fulltext is available in May 2021.
Published Date
2020-05-19
Publication Title
Journal of Materials Chemistry A: materials for energy and sustainability
Volume
volume8
Issue
issue29
Publisher
Royal Society of Chemistry
Start Page
14472
End Page
14481
ISSN
2050-7488
NCID
AA12603290
Content Type
Journal Article
language
英語
OAI-PMH Set
岡山大学
File Version
author
DOI
Web of Science KeyUT
Related Url
isVersionOf https://doi.org/10.1039/D0TA04005C
Funder Name
Japan Society for the Promotion of Science
助成番号
17K06017