Sodium substitution for partial lithium to significantly enhance the?cycling stability of Li₂MnO₃ cathode material

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• 作者：Xin Dong ; Youlong Xu ; Lilong Xiong ; Xiaofei Sun ; Zhengwei Zhang
• 关键词：Sodium substitution ; Cycling stability ; Lithium-rich manganese oxide ; Phase transformation ; Lithium-ion batteries
• 刊名：Journal of Power Sources
• 出版年：2013
• 出版时间：1 December, 2013
• 年：2013
• 卷：243
• 期：Complete
• 页码：78-87
• 全文大小：4912 K

文摘

Monoclinic layered Li₂MnO₃ has been extensively investigated due to its large discharge capacity. However, the poor cycling stability hinders its application as a cathode material of lithium-ion batteries. Herein we present a new strategy of sodium substitution for partial lithium to significantly enhance the cycling stability of Li₂MnO₃ through a conventional solid state reaction. In the electrochemical window of 2.0-4.6?V vs. Li/Li⁺, Li_1.90Na_0.10MnO₃ delivers an initial discharge capacity of 181?mAh?g^?1 with an excellent capacity retention of 99.3 % after 45 cycles at 1/10?C, and 161?mAh?g^?1 with a capacity retention of 98.6 % after 100 cycles at 1/2?C. Sodium substitution for partial lithium is promising to make Li₂MnO₃ be practically applied at a low current density.