An analytical electro-thermal model for Lithium-ion Batteries

Introduction Batteries with lithium-ion chemistry are the preferred candidate to power hybrid and electric vehicles (HEVs), due to their high power density (up to 150 Wh/kg), short charging time, minimal memory effects and selfdischarge (around 5% per month), and long cycling life [1]. Nonetheless, thermal management of large-scale lithium-ion (Li-ion) batteries during high current charge and discharge processes has remained as a challenging task. Design of an effective battery thermal management system (BTMS) is vital for the safety, efficiency, and longevity of Li-ion batteries. In order to develop a practical BTMS for Li-ion batteries, an accurate understanding of heat generation inside the batteries is required. To investigate the thermal behavior of prismatic Li-ion polymer batteries, particularly during discharging, an analytical electro-thermal model is proposed in this study. The model uses the concept of electrical constriction resistance (ECR) to describe excessive heating at the battery tabs with the modest numerical effort. Results from the proposed analytical model are validated by experimentation.