¹²¹Sb M枚ssbauer study of the electrochemical reaction of NiSb₂ vs lithium

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• 作者：C. Villevieille ; C.-M. Ionica-Bousquet ; J.-C. Jumas and L. Monconduit
• 关键词：Sb ; based intermetallic compounds ; Lithium ; ion batteries ; 121Sb M枚ssbauer spectroscopy ; Conversion process
• 刊名：Hyperfine Interactions
• 出版时间：November, 2008
• 出版年：2008
• 期刊代码：18_03043843
• 类别：cp
• 卷：187
• 期：1-3
• 页码：71-79
• 数据来源：sp

摘要

The reaction of a new negative electrode material NiSb₂ vs lithium was investigated by 121Sb M枚ssbauer spectroscopy to highlight the mechanism occurring upon the cycling of the battery. Structural and electronic modifications induced by the reaction with lithium have been characterised for different depths of discharge/charge. The first discharge was clearly identified as a conversion process which leads to the formation of Li₃Sb. On charge, the M枚ssbauer analysis showed that the pristine NiSb₂ is not reconstructed as expected for a conversion reaction, but that the high pressure-NiSb₂ polymorph and antimony are formed. Once the first cycle achieved, a different mechanism takes place upon the second discharge. In a first step, the Sb → Li₂Sb transformation takes place followed by the Li₂Sb → Li₃Sb transformation. In a second step the high-pressure NiSb₂ phase further reacts with Li to form Li₃Sb + Ni0. Thanks to this mechanism, 100%of the initial reversible 520 mAh g − 1 capacity is sustained after 15 cycles.