Predictive modeling of lithium-ion battery degradation: Incorporating SEI layer growth and mechanical stress factors

A physics-based model of lithium-ion batteries (LIBs) has been developed to predict the decline in their performance accurately. The model considers both electrochemical and mechanical factors. During charge and discharge cycles, the solid electrolyte interphase (SEI) layer thickens, leading to increased resistance, higher overvoltage, more lithium deposition, dendrite growth, and reduced discharge capacity. Additionally, graphite expands during lithium insertion and contracts during extraction, causing mechanical stress and cracks. These cracks expose more surface area for SEI growth, intensifying lithium loss. The model also considers the loss of active material within the electrodes, which further reduces discharge capacity. This comprehensive LIB degradation model provides valuable insights for optimizing battery design and improving performance.