Feasibility of Using Li2MoO3 in Constructing Li-Rich High Energy Density Cathode Materials

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• 作者：Jun Ma ; Yong-Ning Zhou ; Yurui Gao ; Xiqian Yu ; Qingyu Kong ; Lin Gu ; Zhaoxiang Wang ; Xiao-Qing Yang ; Liquan Chen
• 刊名：Chemistry of Materials
• 出版年：2014
• 出版时间：May 27, 2014
• 年：2014
• 卷：26
• 期：10
• 页码：3256-3262
• 全文大小：422K
• 年卷期：v.26,no.10(May 27, 2014)
• ISSN：1520-5002

文摘

Layer-structured xLi₂MnO₃路(1 鈥?x)LiMO₂ are promising cathode materials for high energy-density Li-ion batteries because they deliver high capacities due to the stabilizing effect of Li₂MnO₃. However, the inherent disadvantages of Li₂MnO₃ make these materials suffer from drawbacks such as fast energy-density decay, poor rate performance and safety hazard. In this paper, we propose to replace Li₂MnO₃ with Li₂MoO₃ for constructing novel Li-rich cathode materials and evaluate its feasibility. Comprehensive studies by X-ray diffraction, X-ray absorption spectroscopy, and spherical-aberration-corrected scanning transmission electron microscopy clarify its lithium extraction/insertion mechanism and shows that the Mo⁴⁺/Mo⁶⁺ redox couple in Li₂MoO₃ can accomplish the task of charge compensation upon Li removal. Other properties of Li₂MoO₃ such as the nearly reversible Mo-ion migration to/from the Li vacancies, absence of oxygen evolution, and reversible phase transition during initial (de)lithiation indicate that Li₂MoO₃ meets the requirements to an ideal replacement of Li₂MnO₃ in constructing Li₂MoO₃-based Li-rich cathode materials with superior performances.