Abstract Amorphous silicon is a very promising anode material for lithium-ion batteries, but the poor cycle performance owing to volume expansion must be improved before application. In the present study, a series of amorphous FexSi100−x films with different local structures were prepared by magnetron sputtering system. The local structures of the films can be described using the cluster-plus-glue-atom model. For x = 5.3–14.0 at.%, the principal cluster is [Si–Si4], for x = 24.2–46.8 at.%, the principal cluster is [Fe–Si8Fe2], especially for x = 19.1 at.%, the film has both clusters. The films on copper foil substrates were tested as the anode electrode material of lithium-ion batteries. The results show that the cycling stability of the thin film electrode increases with increasing Fe content, but the specific capacity decreases. The impedance of the films also shows two completely different trends with the composition, which further confirms that these Fe–Si amorphous films have different local structures. Especially for the Fe19.1Si80.9 film, the charge transfer between the two electrolyte/electrode interfaces has the two smallest impedances, indicating that the film has the highest charge transfer efficiency.

中文翻译：

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非晶Fe-Si薄膜双局部结构对锂离子电池负极性能的影响

摘要 非晶硅是一种非常有前景的锂离子电池负极材料，但由于体积膨胀导致循环性能差，应用前必须加以改善。在本研究中，通过磁控溅射系统制备了一系列具有不同局部结构的非晶 FexSi100-x 薄膜。薄膜的局部结构可以使用簇加胶原子模型来描述。对于 x = 5.3–14.0 at.%，主簇为 [Si–Si4]，对于 x = 24.2–46.8 at.%，主簇为 [Fe–Si8Fe2]，尤其对于 x = 19.1 at.%，电影有两个集群。铜箔基材上的薄膜作为锂离子电池的负极材料进行了测试。结果表明，薄膜电极的循环稳定性随着Fe含量的增加而增加，但比容量降低。薄膜的阻抗也显示出两种完全不同的成分趋势，这进一步证实了这些 Fe-Si 非晶薄膜具有不同的局部结构。特别是对于Fe19.1Si80.9薄膜，两个电解质/电极界面之间的电荷转移具有最小的两个阻抗，表明该薄膜具有最高的电荷转移效率。