Simulation of hybrid air-cooled and liquid-cooled systems for optimal lithium-ion battery performance and condensation prevention in high-humidity environments

As demand for higher discharge rates surges, the trend towards colder liquid cooling in high-humidity environments poses condensation risks in lithium-ion battery thermal management systems, potentially leading to electrical safety hazards. This study introduces an innovative hybrid air-cooled and liquid-cooled system designed to mitigate condensation in lithium-ion battery thermal management systems (BTMS) operating in high-humidity environments. The proposed system features a unique return air structure that enhances the thermal stability and safety of the batteries by recirculating air through the battery box, thereby utilizing residual heat to prevent condensation. Computational Fluid Dynamics (CFD) simulations were employed to analyze and optimize the system's thermal management performance under various airflow velocities and temperature conditions. The study results show that compared to traditional liquid cooling systems, the proposed hybrid system reduces the condensation area by approximately 39.68 % at a wind speed of 0.5 m/s, and the temperature difference decreases by 0.35 K. The integration of flow deflectors further improves the anti-condensation effect, achieving a phase change rate greater than 0 in the cooling area, thereby enabling condensation-free operation throughout the entire cooling zone. A comprehensive evaluation using the entropy weight-TOPSIS method and nonlinear surface fitting was conducted to assess multiple schemes regarding heat dissipation, anti-condensation measures, and energy consumption. The optimal operating conditions were identified as an airflow velocity of 1.29 m/s and a liquid flow velocity of 0.22 m/s, resulting in a maximum temperature difference of 3.98 K, a maximum temperature of 302.36 K, and energy consumption of air cooling and liquid cooling is 0.158 J and 0.192 J. The proposed composite cooling system with a recirculation structure not only addresses the thermal management challenges of lithium-ion batteries but also effectively ensures the insulation safety of electronic components in high-humidity environments.