Analysis of Thermal Performance of 18650 Li-Ion Battery Based on an Electrochemical-Thermal Coupling Model

Abstract

The research on the thermal performance of cylindrical cells has been a hot topic in the academic and industrial circles because of its mature manufacturing process, good product consistency but poor cooling capacity. In this study, 18650 lithium-ion battery is selected as the object and an electrochemical-thermal coupling model is established with the software of COMSOL Multiphysics, validating by the experimental data. The thermal performance of the battery was simulated and analyzed from different points of views. It is mainly considered that heat production, concluding the discharge rate (discharge current) and the electrode thickness (battery capacity), and heat dissipation, consisted of the ambient temperature, the medium and the flow pattern. The effects on temperature and temperature difference are compared comprehensively and systematically. Our results provide a theoretical basis for battery thermal management.