Evaluation of The Electrochemo-Mechanically Induced Stress in All-Solid-State Li-Ion Batteries
Evaluation of The Electrochemo-Mechanically Induced Stress in All-Solid-State Li-Ion Batteries
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DOI：
10.1149/1945-7111/ab8f5b
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发表时间：
2020-05
影响因子：
3.9
通讯作者：
H. Tian;A. Chakraborty;A. Talin;P. Eisenlohr;Y. Qi
中科院分区：
文献类型：
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作者：
H. Tian;A. Chakraborty;A. Talin;P. Eisenlohr;Y. Qi
由于固体电解液对电极变形的机械约束作用，全固态锂离子电池(ASSLB)的机械性能退化将比传统的液态锂离子电池更为严重。在固体电解液(SE)内部和SE/电极界面上都可能出现裂纹和断裂。建立了一个电化学-力学耦合模型，并用有限元方法对其进行了求解，以评估ASSLB的应力发展。考虑了两个体积变化的来源，即锂浓度变化引起的电极的膨胀/收缩和Se分解引起的Se/电极界面的界面形成。用密度泛函理论(DFT)计算预测了最可能的SE分解反应及其体积变化。研究发现，与SE分解引起的体积变化有关的应力可能比与Li插入/拔出有关的电极体积变化的应力大得多。该模型可用于设计三维ASSLB结构，使其产生的内应力最小。
The mechanical degradation of all-solid-state Li-ion batteries (ASSLBs) is expected to be more severe than that in traditional Li-ion batteries with liquid electrolytes due to the additional mechanical constraints imposed by the solid electrolyte on the deformation of electrodes. Cracks and fractures could occur both inside the solid electrolyte (SE) and at the SE/electrode interfaces. A coupled electrochemical-mechanical model was developed and solved by the Finite Element Method (FEM) to evaluate the stress development in ASSLBs. Two sources of volume change were considered, namely the expansion/shrinkage of electrodes due to lithium concentration change and the interphase formation at the SE/electrode interface due to the decomposition of SEs. The most plausible SE decomposition reactions and their associated volume change were predicted by density functional theory (DFT) calculations. It was found that the stress associated with a volume change due to SE decomposition can be much more significant than that of electrode volumetric changes associated with Li insertion/extraction. This model can be used to design 3D ASSLB architectures to minimize their internal stress generation.