A novel thermal management system for lithium-ion battery modules combining direct liquid-cooling with forced air-cooling

Abstract

The safety, lifespan and performance of lithium-ion battery are closely related to its working temperature. A large amount of heat will be generated inside the battery during working. Therefore, a thermal management system is necessary to cool down the battery. This work develops a novel hybrid battery thermal management system combining direct liquid cooling with forced air cooling. A jacket was designed outside the battery, and the liquid coolant was filled between the battery case and the jacket to form a direct cooling effect. The effects of gap spacing between battery and liquid-cooling jacket, the number of cooling pipelines, liquid flowing rate and fan position on the cooling effects are analyzed by numerical simulations to optimize the design. The findings indicate that the best configuration for the current thermal management system is a 5-mm spacing between the battery and liquid-cooling jacket, a double pipeline liquid-cooling structure, and a horizontal parallel flow of liquid coolant and air. The optimum flow rate of liquid is determined to be 0.002 kg/s, and the air flow rate should be less than 0.4 m/s to save the required energy. The battery thermal management system obtains a good heat dissipation effect at a 4-C discharge rate of batteries. The novelty of the BTMS is that its cooling efficiency is high and can be used to cool the battery pack under high-rate operating conditions. The direct liquid-cooling method has the fire suppression function, which is benefit for the prevention of fires in electric vehicles.