Exotic reaction front migration and stage structure in lithiated silicon nanowires.
Exotic reaction front migration and stage structure in lithiated silicon nanowires.
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DOI：
10.1021/nn502621k
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发表时间：
2014-07
期刊：
影响因子：
17.1
通讯作者：
Lifen Wang;Donghua Liu;Shi-ze Yang;Xuezeng Tian;Guangyu Zhang;Wenlong Wang;E. Wang;Zhi Xu;X. Bai
中科院分区：
文献类型：
--
作者：
Lifen Wang;Donghua Liu;Shi-ze Yang;Xuezeng Tian;Guangyu Zhang;Wenlong Wang;E. Wang;Zhi Xu;X. Bai
纳米结构硅阳极具有极高的能量密度和不需要粉化就能承受大应变的特点，在大功率锂离子电池中得到了迅速的发展。本文利用原位电子显微镜研究了直径小于60 nm的硅纳米线的锂化行为。这项研究表明，自限锂离子直接依赖于原始直径。随着阶段结构的形成，在原始直径略大于自限阈值的纳米线的核心处发生了“穿透”的锂化过程。我们的工作证明了机械应力和局部缺陷在决定介观尺度上反应前沿的迁移和几何形状中的关键作用。这一耐人寻味的发现对硅纳米结构在大功率锂离子电池中的应用具有关键意义。
Nanostructured silicon anodes, which possess extremely high energy density and accommodate large strain without pulverization, have been developed rapidly for high-power lithium ion batteries. Here, using in situ transmission electron microscopy, the lithiation behavior of silicon nanowires with diameters smaller than 60 nm was investigated. The study demonstrated a direct dependence of the self-limiting lithiation on the pristine diameter. A "punch-through" lithiation process at the core of nanowires with pristine diameters slightly larger than the self-limiting threshold is suggested to occur with the consequent formation of a stage structure. Our work demonstrates the crucial role of mechanical stress and local defects in determining the migration and geometry of the reaction front at the mesoscopic scale. This intriguing finding holds critical significance for the application of silicon nanostructures in high-power lithium ion batteries.