Lithium storage in commercial MoS₂ in different potential ranges

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• 作者：Xiangpeng Fang ; Chunxiu Hua ; Xianwei Guo ; Yongsheng Hu ; Zhaoxiang Wang ; Xueping Gao ; Feng Wu ; Jiazhao Wang ; Liquan Chen
• 关键词：Sulfides ; Molybdenum ; Lithium storage mechanism ; Capacitive ; Lithium&ndash ; sulfur battery
• 刊名：Electrochimica Acta
• 出版年：2012
• 出版时间：30 October, 2012
• 年：2012
• 卷：81
• 期：Complete
• 页码：155-160
• 全文大小：1310 K

文摘

Transition metal sulfides are regarded as another type of high-performance anode materials following the transition metal oxides for lithium ion batteries. However, the lithium storage mechanisms of these sulfides are complicated. This work is intended to evaluate the electrochemical performances of molybdenum disulfide (MoS₂) and find out its lithium storage mechanism at different lithium insertion stages. It is found that although the MoS₂ shows excellent cycling stability in different voltage ranges, its structural transition is irreversible in the initial cycling. In contrast to the traditional beliefs, metallic Mo is found inert and Li₂S/S is the redox couple in a deeply discharged MoS₂/Li cell (0.01 V vs. Li/Li⁺). The metallic Mo nanoparticles are believed to be responsible for the enhanced cycling stability of the cell and act as the electronically conducting phase in the capacitive energy storage on the interfaces or grain boundaries of Mo/Li₂S_x nanocomposite. In addition, the Mo/Li₂S nanocomposite can be used as a cathode material for lithium-sulfur batteries.