Classification of spatio‐temporal patterns in charging and discharging of Li‐ion batteries

Abstract

We classify the dynamic patterns that emerge in charging or discharging of Li-ion batteries, under galvanostatic conditions, using simulations of the two-phase onedimensional (1D) porous electrode model. This work examines the effect of the exchange current function, R 0 (X), which expresses the nature of kinetics. This extends our previous study with R 0 = 1 where the same pattern emerges in charging or discharging, whether as a homogeneous or a step-wise process made of multiple symmetry breaking events. With commonly-used asymmetric R 0 (X), the emerging patterns may be one of the two above or as fronts that follow single SB event and the lithiation/delithiation behaviors are different. These effects are clear when parameters are uniform; nonuniformity leads to noise that mask the behavior. The full four-variable model exhibits SB, even in absence of noise, since the liquid potential gradient (ϕ l ) works like a perturbation. This similarity allows us to derive approximations to the full model behavior.