Performance assessment of a novel localized cooling system for battery thermal management at high ambient conditions

Battery thermal management systems are crucial for electric vehicles to ensure the performance, longevity, and safety of lithium-ion batteries. Thermal management systems must be lightweight to improve vehicle efficiency and robust enough to operate effectively at high temperatures like 40 °C. However, research on cooling systems that focuses on reducing weight, minimizing power consumption, and ensuring performance and battery health in high temperatures is limited but crucial for the industry. This study proposes a lightweight T-shaped cold plate for the 60Ah pouch cell, and its capabilities are demonstrated at the cell level through experiments performed at high ambient temperatures of 40 °C and 35 °C during 1C charging and 2C discharging cycles. The scalability of the T-shaped cold plate is further validated by extending the design from the cell level to the module level using numerical studies. Performance metrics are developed to optimize coolant mass flow rate and inlet temperature, balancing battery health and energy consumption. An optimal mass flow rate of 7 kg/h and inlet temperature of 35 °C is identified for both 40 °C and 35 °C ambient conditions. The intermittent coolant supply reduced energy consumption by 36.9 % and 59 % compared to continuous cooling at 40 °C and 35 °C ambient temperatures, respectively. Additionally, this intermittent supply minimized temperature heterogeneity on the cell surface to 3 °C and 2.1 °C for 40 °C and 35 °C ambient temperatures, respectively. At the module level, T-shaped cold plates keep the temperature rise below 45 °C using a scaled-up mass flow rate of 35 kg/h and an inlet temperature of 35 °C in a 40 °C ambient condition. The T-shaped cold plate structures constitute 20.7 % of the total module weight and offer scalability to pack-level applications. This makes the TCP a potential solution for lightweight and efficient thermal management in electric vehicles, fostering the electrification journey.