Fracture predictions based on a coupled chemo-mechanical model with strain gradient plasticity theory for film electrodes of Li-ion batteries
Fracture predictions based on a coupled chemo-mechanical model with strain gradient plasticity theory for film electrodes of Li-ion batteries
复制标题
基于应变梯度塑性理论的化学机械耦合模型的锂离子电池薄膜电极断裂预测
DOI：
10.1016/j.engfracmech.2021.107866
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发表时间：
2021-07-07
影响因子：
5.4
通讯作者：
Ma, Zengsheng
中科院分区：
文献类型：
--
作者：
Chen, Yaoxing;Sang, Mengsha;Ma, Zengsheng
锂离子电池的大容量电极在充放电过程中不可避免地会产生较大的体积变形，这是由于高扩散应力引起的。在本文中，我们首先建立了一个新的弹塑性模型，用于描述Li原子迁移产生的高密度位错缺陷框架内的扩散诱发形变。然后，采用应变梯度塑性理论和有限元模拟相结合的方法，分析了基于Li浓度变化的电极材料的膜尺寸效应、扩散应力、塑性屈服和硬化。最后，根据牵引分离定律，表征了刚性衬底上的活性薄膜材料(厚度分别为150、200和250 nm)的界面损伤和剥离。
High-capacity electrodes in Li-ion batteries inevitably undergo a large volume deformation originating from high diffusion-induced stresses during charging and discharging processes. In this paper, we firstly develop a new elastoplastic model for describing diffusion-induced defor-mation in the framework of high-density dislocation defects generated due to the migration of Li atoms. Then, we analyze the film size effect, diffusion-induced stress, plastic yielding, and hardening of electrode materials based on the evolutions of Li concentration by a strategy combining the strain gradient plasticity theory and finite element simulations. Finally, according to the traction-separation law, interface damage and debonding are characterized in the active film materials (with a thickness of 150, 200, and 250 nm, respectively) on a rigid substrate.