Thermal Simulation Analysis of a Lithium-Ion Battery

Lithium – Ion batteries are now extensively used in electric vehicles (EV) as well as in renewable power generation applications for both on-grid and off grid storage. Some of the major challenges with batteries for electric vehicles are the requirement of high energy density, compatibility with high charge and discharge rates while maintaining high performance, and prevention of any thermal runaway conditions. The objective of this research is to develop a computer simulation model for coupled electrochemical and thermal analysis and characterization of a lithium-ion battery performance subject to a range of charge and discharge loading, and thermal environmental conditions. The electrochemical model includes species and charge transport through the liquid and solid phases of electrode and electrolyte layers along with electrode kinetics. The thermal model includes several heat generation components such as reversible, irreversible and ohmic heating, and heat dissipation through layers of battery cell. Simulation is carried out to evaluate the electrochemical and thermal behavior with varying discharge rates. Results demonstrated a strong variation in the activation and ohmic polarization losses as well as in higher heat generation rates. Results show variation of different modes and order of cell heat generation rates that results in a higher rate of cell temperature rise as battery cell is subjected to higher discharge rates. The model developed will help in gaining a comprehensive insights of the complex transport processes in a cell and can form a platform for evaluating number new candidates for battery chemistry for enhanced battery performance and address safety issues associated with thermal runaway.