Evidence of Copper Separation in Lithiated Cu6Sn5 Lithium-Ion Battery Anodes
Evidence of Copper Separation in Lithiated Cu6Sn5 Lithium-Ion Battery Anodes
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DOI：
10.1021/acsaem.9b02014
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发表时间：
2020-01-01
影响因子：
6.4
通讯作者：
Nogita, Kazuhiro
中科院分区：
文献类型：
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作者：
Tan, Xin F.;Yang, Wenhui;Nogita, Kazuhiro
金属间化合物Cu6Sn5、NiSi2、CuGa2等是替代碳基锂离子电池负极的重要候选材料。然而，这些阳极的锂化反应通常涉及非活性相的分离，这是一个缓慢的过程，延缓了锂化动力学，并使它们作为应力缓冲的作用失效。本研究利用先进的电子显微镜技术对锂离子化Cu6Sn5阳极中分离出的铜进行了可视化研究。在Li(13+y)Sn5和Li13Cu6Sn5两种相中，均一分布着3~4 nm的铜纳米球，表明在Li(13+y)Sn5/Li13Cu6Sn5相界面处，铜是通过远程扩散的方式从反应中心迁移出来的。
Intermetallics such as Cu6Sn5, NiSi2, and CuGa2 etc., are promising candidate materials to replace carbon-based lithium-ion battery anodes. However, the lithiation reactions of these anodes often involve the separation of the inactive phases, a slow process that retards the lithiation kinetics and deactivates their role as a stress buffer. This research visualizes the separated Cu in a lithiated Cu6Sn5 anode by advanced transmission electron microscopy techniques. Cu nanospheres of 3-4 nm are found homogeneously distributed in both Li(13+y) Sn-5 and Li13Cu6Sn5 phases, suggesting that Cu is transported by long-range diffusion from the reaction site at the Li(13+y)Sn5/Li13Cu6Sn5 phase boundaries.