Acta Mechanica Solida Sinica ( IF 2.2 ) Pub Date : 2021-10-02 , DOI: 10.1007/s10338-021-00257-5 Feng Wang 1 , Kai Zhang 1 , Bailin Zheng 1
For the development of the fast charging technology of lithium-ion batteries, describing the rapid transient mass diffusion process accurately is the premise to avert the mechanical degradation caused by the diffusion-induced stress. In this paper, we present a diffusion-elasticity model based on the finite deformation theory with the consideration of non-local effects of mass transfer. The proposed model is then applied to analyze the evolution and distribution of stress and lithium concentration in a silicon electrode during the rapid charging process under potentiostatic operation. The cases with and without the contribution of non-local diffusion effects are both calculated for comparative analysis. The dependence of the influence of non-local effects on diffusion relaxation time \(\tau _{\mathrm{0}} \) is discussed. The results show that a diffusive wave appears when the value of \(\tau _{\mathrm{0}}\) is sufficiently large, and it moves inside gradually during the rapid charging process, which is qualitatively consistent with the results from literature.
中文翻译:
锂离子电池球形硅电极中快速瞬态质量扩散引起的非局域效应
对于锂离子电池快速充电技术的发展,准确描述快速瞬态质量扩散过程是避免由扩散引起的应力引起的机械退化的前提。在本文中,我们提出了一种基于有限变形理论的扩散弹性模型,同时考虑了传质的非局部效应。然后应用所提出的模型来分析在恒电位操作下快速充电过程中硅电极中应力和锂浓度的演变和分布。有和没有非局部扩散效应贡献的情况都被计算用于比较分析。非局部效应对扩散弛豫时间影响的依赖性\(\tau _{\mathrm{0}} \)进行了讨论。结果表明,当\(\tau _{\mathrm{0}}\)的值足够大时,会出现扩散波,并在快速充电过程中逐渐向内移动,与文献结果定性一致.