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ID 60290
著者
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
抄録
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.
備考
This fulltext is available in May 2021.
発行日
2020-05-19
出版物タイトル
Journal of Materials Chemistry A: materials for energy and sustainability
8巻
29号
出版者
Royal Society of Chemistry
開始ページ
14472
終了ページ
14481
ISSN
2050-7488
NCID
AA12603290
資料タイプ
学術雑誌論文
言語
English
OAI-PMH Set
岡山大学
論文のバージョン
author
DOI
Web of Science KeyUT
関連URL
isVersionOf https://doi.org/10.1039/D0TA04005C
助成機関名
日本学術振興会
助成番号
17K06017