Mechanistic modeling of Li plating in lithium-ion batteries

Li plating is considered as the major cause for the capacity degradation, resistance increase, and early short circuit of the cell. Due to the highly nonlinear and interdisciplinary nature, quantitative modeling of the Li plating process at the cell level is not available. Herein, we established a physics-based detailed model to describe the Li plating behaviors in a pouch cell level. The distribution of the current density and over-potential accurately predict the higher possibility of Li plating in the inner anode layers than the out layers. We discover that the larger thickness of the anode is more prone to have Li plating due to the liquid phase potential. The conductivity of electrolyte and diffusivity of Li-ion in cathode increase the Li plating risk while higher diffusivity of Li-ion in anode leads to a reduced risk. Battery charging mode also has a nontrivial influence on the Li plating probability. More importantly, the tab positions play a dominant role in the Li plating risk. Results unlock the fundamental working mechanism of Li plating in various design parameters and working scenarios, as well as provide a detailed modeling framework for the guidance of the next-generation long-cycle battery designs.