Optimization of thermal management performance for lithium-ion batteries using helical tube liquid cooling integrated with phase change materials and fins

The rapid growth of new energy vehicles has driven a persistent demand for improved charging. However, high-rate charging and discharging impose stricter temperature control requirements on the vehicle's battery pack. The work designed a sandwich-type spiral liquid cooling structure, with numerical simulations performed at a rate of 5C. The influences of the number of spiral pipes, fluid velocity, and pipe geometry on the battery temperature were examined. An L 16 (4 3 ) orthogonal experimental design was employed to analyze the weight of these three factors. The increased number of spiral pipes reduced the peak battery temperature, while an even number of pipes enhanced the uniformity of temperature distribution. However, this increase resulted in greater structural complexity of the cooling system. The increased fluid velocity reduced both the peak temperature and the temperature difference of the battery within an appropriate range. Once the velocity exceeded a critical level, improved thermal performance became marginal. The geometry of the spiral pipes affected the battery temperature. An appropriate design reduced the peak temperature and temperature difference, lightening the overall weight of the cooling system. Based on orthogonal analysis, weight was calculated to provide design guidelines for future researchers. When the flow rate was 0.05 m/s in two rectangular spiral pipes, the battery achieved optimal cooling performance. The maximum battery temperature and temperature difference were maintained at 35.04 and 4.8 °C, respectively.