Thermal performance analysis of 18,650 battery thermal management system integrated with liquid-cooling and air-cooling

Abstract

The growing emphasis on developing high-performance battery thermal management systems to maintain optimal temperatures in lithium-ion batteries makes it a key priority in the electric vehicle industry. Therefore, this study aims to explore a composite thermal management system that leverages both air and liquid cooling. The study investigates the thermal effects of varying liquid flow rates and air flow rates in a computational fluid dynamics model for an 18,650 battery pack discharged at 2C. A three-dimensional model is built in ANSYS SCDM, and the mesh is generated using Fluent Meshing. Subsequently, the model is imported into Fluent to solve the turbulent flow using the k-ε model. The obtained results provide a temporal characterization of the battery thermal management system. Research indicates that the utilization of the composite thermal management system can reduce the temperature difference of the battery pack to a minimum of 3.73 K. Increasing air and liquid flow rates also decrease the highest temperature to 317.38 K. Moreover, increasing air and liquid flow rates reduce entropy production in the thermal management system. Notably, air flow affects entropy production in both air and fluid regions, making it a more effective means to reduce entropy production. In conclusion, the proposed composite thermal management system improves the cooling performance of traditional thermal management systems and provides guidance for efficient battery thermal management design.