Unveiling the multi-physical contributions in lithium plating for large cylindrical lithium-ion batteries during fast-charging

Abstract

Large cylindrical lithium-ion batteries (LIBs), such as 46XX LIBs, are promising for electric vehicles due to their high energy density and fast charging capabilities. It is crucial to address safety issues associated with lithium plating during fast charging. Extensive research has focused on individual factors affecting lithium plating, such as temperature and stress. Nevertheless, a comprehensive evaluation is still lacking for large LIBs with complex structures, which experience significant temperature and stress gradients during fast charging. Here, we propose a modeling approach to understand the coupling of electrochemical processes with temperature and stress within a jelly roll. The mechanical-thermal-electrochemical (MTE) coupled model is validated through a combination of external measurement and CT-based internal deformation analysis. We establish a battery-scale distribution of lithium plating risks along the winding direction and clarify the most important factors, including the tab design, charging current, stress, and temperature distributions, and explore the interrelationships between them. Uneven stress distribution leads to a positional preference for lithium plating, potentially leading to an underestimation of lithium plating risk. This method demonstrates extensive engineering applications of the MTE coupled mechanisms and their roles in battery performance, degradation, and safety from structure design, manufacturing optimization, and operating conditions.