A novel thermal management system combining phase change material with wavy cold plate for lithium-ion battery pack under high ambient temperature and rapid discharging

•A novel hybrid BTMS composed of PCM and counterflow wavy cold plate is proposed.•The BTMS exhibits excellent performance in terms of temperature uniformity.•1 mm thickness PCM is ideal for battery temperature uniformity and energy density.•Effects of the coolant flow direction, flow rate, and temperature are studied. Thermal management is crucial for decreasing the risk of thermal runaway during rapid discharge of lithium-ion batteries under high ambient temperatures. In this study, a novel hybrid battery thermal management system (BTMS) combining phase change material (PCM) with wavy liquid cold plate is designed for a cylindrical battery pack. On the premise that the simulation accuracy is verified by experiments, the BTMS parameters are quantitatively investigated through simulation. The results indicate that the temperature uniformity of the battery pack can be improved by adopting the coolant counterflow flow with inlets away from the batteries. PCM with 1 mm thickness is optimal for the battery pack temperature uniformity, energy density, and PCM utilization rate. Setting the coolant mass flow rate to 3 × 10-3 kg/s can save energy consumption, while limiting the maximum temperature and temperature difference to 49.98 °C and 3.39 °C, respectively. Moreover, the coolant inlet temperature should be close to that of the pack and PCM phase change to improve temperature uniformity and PCM utilization rate. The novelty of the BTMS is the large contact area with cylindrical batteries, which shows excellent thermal performance and improves the thermal safety of batteries for rapid discharge under high ambient temperatures.