A model for the mechanical response of electrode particles induced by lithium diffusion in Li-ion batteries
A model for the mechanical response of electrode particles induced by lithium diffusion in Li-ion batteries
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DOI：
10.1007/s00707-014-1096-2
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发表时间：
2014-02
期刊：
影响因子：
2.7
通讯作者：
A. Drozdov
中科院分区：
文献类型：
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作者：
A. Drozdov
推导了客体原子扩散驱动的主介质粘塑性响应的本构模型。参照捕获概念，客体原子的两种状态被区分：移动的和固定的（由于与主体基质合金化）。基于自由能不平衡不等式，建立了移动的原子输运和俘获的反应扩散方程，以及基质材料力学行为的应力应变关系。将本构方程应用于球形电极颗粒在嵌锂作用下的应力分析。数值模拟表明，该模型预测的能力（i）形成一个尖锐的界面之间的区域丰富和贫乏的客体原子，（ii）传播的界面以恒定的速度，和（iii）电极颗粒的尺寸依赖性断裂。
A constitutive model is derived for the viscoplastic response of a host medium driven by diffusion of guest atoms. With reference to the trapping concept, two states of a guest atom are distinguished: mobile and immobilized (due to alloying with the host matrix). Reaction–diffusion equations for the transport of mobile atoms and their trapping, as well as stress–strain relations for the mechanical behavior of the host material, are developed based on the free-energy imbalance inequality. The constitutive equations are applied to the analysis of stresses in a spherical electrode particle under insertion of lithium. Numerical simulation demonstrates the ability of the model to predict (i) formation of a sharp interphase between regions rich and poor in guest atoms, (ii) propagation of the interphase with a constant velocity, and (iii) size-dependent fracture of electrode particles.