Modeling effect of magnetic field on multicycle aging under fast charging of lithium battery

Fast charging induces severe interfacial anodic degradation in lithium-ion batteries (LIBs) due to poor ionic transport and intercalation limitations. Computational modeling offers access to in-depth analysis of the degradation pathways that influence battery performance, particularly in harsh operating conditions. In this paper, a pseudo three-dimensional physics-based model is developed to study the effects of external magnetic field (MF) on degradation mechanisms, such as solid electrolyte interface (SEI) (re)growth, lithium plating/stripping, and loss of active material (LAM) during battery aging. The model simulates nickel‑manganese‑cobalt/graphite cells over a range of charging rates (1–6C) and MF (0 kG – 6 kG). Under the influence of the MF, the charged species/ions in the electrolyte experience the Lorentz force, which induces a transverse acceleration, leading to spiral motion of the ions, and thus improving mass transport and homogenizing ionic transport. The results indicate that the influence of MF is stronger at extreme fast charging conditions (4 – 6C) due to a larger magnetohydrodynamic effect. An 8.5% capacity enhancement is observed at 6C charging rate and 6 kG MF. A subtle improvement in capacity is found at higher MF (4–6 kG) under fast charging conditions, hence reducing the field and ensuing energy needs to achieve the most significant possible capacity gain. The developed model can serve as a guide for designing a LIB battery pack with an external MF.