Performance analysis of micro-channelled liquid cooled battery thermal management system for Li-Ion battery

Abstract The increasing demand for high-performance electric vehicles underscores the need for efficient battery thermal management systems to ensure optimal performance and longevity of lithium-ion batteries. However, existing battery cooling methods often struggle to maintain uniform temperature distributions and effective heat dissipation, leading to performance degradation and safety concerns. To address these challenges, this study proposes an innovative liquid-cooled, microchannel-based system to manage the thermal behavior of a cylindrical 21700-type lithium-ion battery pack comprising 10 cells. This work aims to rigorously investigate the effects of varying Reynolds numbers and mass flow rates on critical performance parameters, including battery pack temperature, temperature uniformity, convective heat transfer coefficient, coolant outlet temperature, and pressure drop. A three-dimensional simulation model was employed to analyze the thermal and hydraulic behavior of the proposed battery thermal management systems. The results demonstrate that increasing the Reynolds number from 400 to 700 significantly enhances cooling performance, reducing the maximum battery pack temperature from 38.69 °C to 34.25 °C and decreasing the temperature gradient from 2.45 °C to 1.86 °C. However, the improvement increases the pressure drop from 3410 Pa to 3990 Pa, necessitating more powerful pumping systems. Furthermore, the investigation reveals that the proposed microchannel design enables efficient cooling at lower mass flow rates, leading to up to a 95% reduction in coolant requirements. The convective heat transfer coefficient improved by up to 200% at higher Reynolds numbers than conventional designs. These findings highlight an important energy trade-off, as increasing the Reynolds number enhances heat dissipation, it also leads to higher pumping power requirements, rising from 0.04 W to 0.14 W.