Electrochemical activities in Li2 MnO3

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Detail(s)

Original languageEnglish
Journal / PublicationJournal of the Electrochemical Society
Volume156
Issue number6
Publication statusPublished - 2009
Externally publishedYes

Abstract

Li2 MnO3 is shown to be electrochemically active, with a maximum charge capacity of ∼350 mAhg and a discharge capacity of ∼260 mAhg at 25°C. A total of 1 mole of Li can be extracted from Li [Li13 Mn23] O2, and the first cycle efficiency is ∼66% regardless of state of charge. Larger charge-discharge capacity is obtained from materials with smaller particle size and larger amount of stacking faults. Composition and structural analyses indicate that Li are removed from both the Li and transitional metal layers of the material during charging. Results from X-ray-absorption fine-structure measurements suggest that the valence of Mn remains at 4+ during charging but is reduced during discharging. Charging is accompanied by gas generation: at 25°C, oxygen is the main gas detected, and the total amount accounts for ∼18 mole of O2 generation from Li [Li13 Mn23] O2. At an elevated temperature, amount of C O2 increases due to electrolyte decomposition. Li2 MnO3 shows poor cycle performance, which is attributed to phase transformation and low charge-discharge efficiency during cycling. Low first-cycle efficiency, gas generation, and poor cycle performance limit the usage of Li2 MnO3 in practical batteries. © 2009 The Electrochemical Society.

Citation Format(s)

Electrochemical activities in Li2 MnO3. / Yu, Denis Y. W.; Yanagida, Katsunori; Kato, Yoshio; Nakamura, Hiroshi.

In: Journal of the Electrochemical Society, Vol. 156, No. 6, 2009.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review