Prediction of Li-ion Battery Module Performance under Running Condition Based on "Multifactorial Degradation Model"

Abstract

The degradation-thermal coupled simulations of Li-ion battery module have been performed assuming running condition of automotive vehicle. Discharge/charge simulation was based on Single Particle model (SP model), which consists of electrochemical, mass transfer and heat transfer equations. In this study, “Multifactorial degradation model” that we have recently developed was adopted in order to estimate resistance increase and capacity fade with cycle. The model includes side reactions such as growth of passive SEI (Solid Electrolyte Interface), structure transition of positive electrode and detachment between active particles. Each parameter to perform calculation was determined for test battery, composed of typical NCM (LiNixMnyCozO2)-graphite system. As a result, SEI thickness of each battery cell grew with current cycle and the variance increased under typical US-06 mode.