From chemistry to mechanics: bulk modulus evolution of Li-Si and Li-Sn alloys via the metallic electronegativity scale.
From chemistry to mechanics: bulk modulus evolution of Li-Si and Li-Sn alloys via the metallic electronegativity scale.
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DOI：
10.1039/c3cp52997e
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发表时间：
2013-09
期刊：
影响因子：
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通讯作者：
Keyan Li;Hui Xie;Jun Liu;Zengsheng Ma;Yichun Zhou;D. Xue
中科院分区：
文献类型：
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作者：
Keyan Li;Hui Xie;Jun Liu;Zengsheng Ma;Yichun Zhou;D. Xue
针对高性能锂离子电池负极合金的工程化，提出了一种基于金属电负性、合金成分和配方体积定量估算二元合金体积模量的方法。基于我们提出的潜在观点，EN作为一个基本的化学概念可以扩展为表征锂离子电池负极材料Li-Si和Li-Sn合金力学性能的一个重要物理参数。二元合金的体积弹性模量与平均金属EN和合金原子密度的组合成线性关系。计算了不同Li含量的Li-Si合金和Li-Sn合金的体积模量，与文献报道的结果吻合较好。Li-Si和Li-Sn合金的体积模量随着Li含量的增加而降低，导致合金的弹性软化，从EN的观点来看，这本质上是由于合金中的组分化学键强度降低引起的。这项工作提供了一个深刻的理解的Si和Sn阳极的锂离子电池的机械故障，并允许预测的组成依赖于各种锂化合金的体积模量的基础上的化学式，金属EN和电池体积（或合金密度），没有结构的细节要求。
Toward engineering high performance anode alloys for Li-ion batteries, we proposed a useful method to quantitatively estimate the bulk modulus of binary alloys in terms of metallic electronegativity (EN), alloy composition and formula volume. On the basis of our proposed potential viewpoint, EN as a fundamental chemistry concept can be extended to be an important physical parameter to characterize the mechanical performance of Li-Si and Li-Sn alloys as anode materials for Li-ion batteries. The bulk modulus of binary alloys is linearly proportional to the combination of average metallic EN and atomic density of alloys. We calculated the bulk moduli of Li-Si and Li-Sn alloys with different Li concentrations, which can agree well with the reported data. The bulk modulus of Li-Si and Li-Sn alloys decreases with increasing Li concentration, leading to the elastic softening of the alloys, which is essentially caused by the decreased strength of constituent chemical bonds in alloys from the viewpoint of EN. This work provides a deep understanding of mechanical failure of Si and Sn anodes for Li-ion batteries, and permits the prediction of the composition dependent bulk modulus of various lithiated alloys on the basis of chemical formula, metallic EN and cell volume (or alloy density), with no structural details required.