Experimental calibration of a Cahn-Hilliard phase-field model for phase transformations in Li-Sn electrodes
Experimental calibration of a Cahn-Hilliard phase-field model for phase transformations in Li-Sn electrodes
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DOI：
10.1149/2.0701613jes
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发表时间：
2016-09
期刊：
影响因子：
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通讯作者：
Srivatsan Hulikal;Chun-Hao Chen;E. Chason;A. Bower
中科院分区：
文献类型：
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作者：
Srivatsan Hulikal;Chun-Hao Chen;E. Chason;A. Bower
采用实验、数值模拟和解析计算的方法，对经历了从锡到Li2Sn5转变的Li-Sn薄膜电极的扩散界面Cahn-Hilliard模型进行了标定。结果表明，在Cahn-Hilliard方程中可以使用浓度梯度相关的迁移率来赋予界面有限的迁移率并捕捉其非平衡行为。通过对比实验和模拟，提取了Li-Sn的自由能、Li在锡和Li2Sn5中的扩散系数、表面反应的交换电流密度以及锡/Li2Sn5界面的迁移率。讨论了有限界面迁移率对实际电池电极的影响。
Experiments, numerical simulations, and analytical calculations are used to calibrate a diffuse-interface Cahn-Hilliard model of Li-Sn thin film electrodes that experience a transformation from Sn to Li2Sn5. It is shown that a concentration-gradient dependent mobility can be used in the Cahn-Hilliard equation to give the interface a finite mobility and capture its nonequilibrium behavior. Comparing experiments and simulations, the free-energy of Li-Sn, diffusivity of Li in Sn and Li2Sn5, the exchange current density for the surface reaction, and the mobility of the Sn/Li2Sn5 interface are extracted. The implications of finite interface mobility for practical battery electrodes are discussed.