Morphological defects contribute to chronic and acute failures of batteries. The development of these morphological defects entails the multiscale chemo-mechanical coupling associated with internal mechanical stress. The mechanical stress, caused by anisotropic structural, chemical and state of charge (SOC) heterogeneities, is released through crack formation, undermining the continuous diffusion pathways of electrons and ions and creating fresh surfaces for electrode–electrolyte side reactions. The understanding of chemomechanical interplay has remained at the descriptive level, thus, the quantification or model to fingerprint these processes is highly desired. Herein, we systematically investigate the mesoscale morphological defects within LiNi_0.6Mn_0.2Co_0.2O₂ secondary particles that have gone through fast-charging conditions. With the advanced synchrotron X-ray tomography, we nondestructively pierce the internal volume of secondary particles and quantify the morphological outcomes of the crack formation, such as porosity and internal surface area. We then develop a numerical model to predict the crack-induced diffusion deterrent of electrons and lithium ions. The mismatch between the local ionic and electronic conductivity can lead to highly heterogeneous SOC distribution in secondary particles, which exponentially deteriorates as the current density increases. Our incisive investigation of chemomechanical interplay and fast-charging can inform a knowledge base to accelerate the discovery of advanced materials that are resilient against chemomechanical failures.

形态缺陷会导致电池的慢性和急性故障。这些形态缺陷的发展需要与内部机械应力相关的多尺度化学机械耦合。由各向异性的结构，化学和电荷状态（SOC）异质性引起的机械应力通过裂纹形成释放，破坏了电子和离子的连续扩散路径，并为电极-电解质副反应创造了新的表面。对化学机械相互作用的理解仍停留在描述性水平上，因此，非常需要量化或指纹识别这些过程的模型。在本文中，我们系统地研究了LiNi _0.6 Mn _0.2 Co _0.2内的中尺度形貌缺陷Ø ₂经过快速充电条件的二次粒子。使用先进的同步加速器X射线断层扫描，我们可以无损地刺穿次级颗粒的内部体积，并量化裂纹形成的形态结果，例如孔隙率和内部表面积。然后，我们建立一个数值模型来预测裂纹诱导的电子和锂离子的扩散威慑力。局部离子导电率和电子导电率之间的不匹配会导致次级粒子中的SOC分布非常不均匀，随着电流密度的增加，SOC分布呈指数级下降。我们对化学机械相互作用和快速充电的深入研究可以为知识库提供信息，以加快发现可抵抗化学机械故障的先进材料的速度。