Irreversible lithium storage during lithiation of amorphous silicon thin film electrodes studied by in-situ neutron reflectometry
Irreversible lithium storage during lithiation of amorphous silicon thin film electrodes studied by in-situ neutron reflectometry
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DOI：
10.1016/j.jpowsour.2017.05.095
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发表时间：
2017-08
影响因子：
9.2
通讯作者：
B. Jerliu;E. Hüger;M. Horisberger;J. Stahn;H. Schmidt
中科院分区：
文献类型：
--
作者：
B. Jerliu;E. Hüger;M. Horisberger;J. Stahn;H. Schmidt
非晶硅是一种很有前景的高容量锂离子电池负极材料。然而，该材料的一个巨大缺点是循环过程中发生的大量容量损失导致性能不稳定。在这项研究中，我们通过前十个循环的原位中子反射实验研究了非晶硅薄膜电极恒电流锂化过程中发生的容量损失。根据中子散射长度密度和膜厚度的分析确定，容量损失是由于电极中锂的不可逆存储造成的。循环过程中储存的锂量增加到第10次循环后最大理论容量的20%。讨论了可能的解释。
Amorphous silicon is a promising high-capacity anode material for application in lithium-ion batteries. However, a huge drawback of the material is that the large capacity losses taking place during cycling lead to an unstable performance. In this study we investigate the capacity losses occurring during galvanostatic lithiation of amorphous silicon thin film electrodes byin-situneutron reflectometry experiments for the first ten cycles. As determined from the analysis of the neutron scattering length density and of the film thickness, the capacity losses are due to irreversible storage of lithium in the electrode. The amount of stored lithium increases during cycling to 20% of the maximum theoretical capacity after the 10th cycle. Possible explanations are discussed.