Electrochemical Analysis of High Capacity Li-Ion Pouch Cell for Automotive Applications

Major original equipment manufacturers (OEMs) have already marketed electric vehicles in large scale but apart from business strategies and policies, the real engineering problems must be addressed. Lithium-ion batteries are a promising technology for energy storage; however, their low energy density and complex electro-chemical nature, compared to fossil fuels, presents additional challenges. Their complex nature and strong temperature dependence during operation must be studied with additional accuracy, capable to predict their behavior. In this research, a pseudo two dimensional (P2D) electro-chemical model, for a recent high capacity NMC pouch cell for automotive applications is developed. The electrochemical model with its temperature dependent parameters is validated at high, low, and reference temperature within 10°C to 50°C temperature range. For each temperature various discharge C-rates to accurately replicate the battery cell operational conditions. The overall goodness of the model is proven with limited RMS errors in all the cases. Low temperatures and high C-rates are discovered to limit sensibly the battery performances. The complete analysis provides valuable design considerations for the battery thermal management system (BTMS) to enhance performance, cycle life and safety of future electrified vehicle energy storage systems.