Enabling Microscale Simulations for Long-Term Aging of Li-Ion Batteries

In this work we consider a microscale electrochemical model for Li-ion batteries which allows for detailed insights into local transport and degradation processes on the porous electrode microstructures. The model captures the growth of the solid electrolyte interphase (SEI), one of the major aging effects in Li-ion batteries. Due to the computational complexity of such a model, continuous simulation of long-term degradation studies is not applicable. Therefore, we extend on a previously introduced extrapolation scheme that allows to reduce the simulation time for cyclic operation protocols, which are commonly used to determine cell aging characteristics. We investigate convergence of the scheme with decreasing uniform extrapolation step sizes and compare different non-uniform step size controls for a fixed number of steps. Furthermore, a parameter study for the SEI model is performed to illustrate the impact on the aging results and analyse the robustness of the deployed numerical solver.