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ID 52844
フルテキストURL
著者
Gotoh, Kazuma Graduate School of Natural Science & Technology, Okayama University
Izuka, Misato Graduate School of Natural Science & Technology, Okayama University
Arai, Juichi Yamaha Motor Co., Ltd.
Okada, Yumika Yamaha Motor Co., Ltd.
Sugiyama, Teruyasu Division of Chemistry, Graduate School of Science, Kyoto University
Takeda, Kazuyuki Natl Inst Mat Sci
Ishida, Hiroyuki Graduate School of Natural Science & Technology, Okayama University
抄録
Lithium ion cells comprising actual components of positive electrodes (LiCoO2, LiNixCoyAlz, and LiMn2O4) and negative electrodes (graphite and hard carbon) were assembled for in situ7Li nuclear magnetic resonance (NMR) experiments. The 7Li NMR measurements of the cells revealed a “relaxation effect” after overcharging: a decrease of the signal assigned to Li metal deposited on the negative electrode surface by overcharging. The reduction of the Li metal signal was inversely proportional to the increase of the signal of lithium stored in carbon. Therefore, the effect was ascribed to absorption of deposited lithium into the carbon of negative electrodes. The effect, which occurred rapidly in a few hours, reached an equilibrium state at 8–15 h. The slight shift of deposited metal suggests that dendritic Li easily re-dissolved, although larger Li particles remained. A hard carbon electrode has a greater effect of Li metal relaxation than graphite electrodes do, which is explainable by the bufferable structure of the carbon. Results are expected to be important for the discussion of the state of lithium, and for safer battery design.
発行日
2014-11
出版物タイトル
Carbon
79巻
開始ページ
380
終了ページ
387
ISSN
0008-6223
NCID
AA00598943
資料タイプ
学術雑誌論文
言語
English
著作権者
© 2014 Elsevier Ltd. All rights reserved.
論文のバージョン
author
査読
有り
DOI