Investigation on enhancing thermal performance of the li-ion battery pack with fishbone channel liquid cooling plate and optimized flow channels

Effective thermal management is essential for ensuring the safety and high performance of electric vehicle battery packs. This paper investigates the optimization of a fishbone flow channel structure through three strategies: a tapered main channel, reduced rear branch width, and the addition of branch flow channels. Numerical results from ANSYS Fluent indicate that compared to the baseline fishbone channel, a tapered design with a 2 mm outlet width reduces the maximum temperature to 37.21°C, a 0.12°C decrease, and lowers the temperature standard deviation by 0.04°C to 0.51°C. However, a 12% pressure drop increase offsets the 7% gain in the heat taken away by the coolant, limiting the improvement in the comprehensive performance evaluation factor to only 0.7%.Reducing the rear branch width to 2 mm constrains the temperature standard deviation to 0.50°C, which is 0.05°C lower than the original channel, with minimal impact on other metrics. Expanding branch channels is the most effective strategy for heat transfer enhancement. Specifically, a structure with a 6 mm branch length reduces the maximum temperature by 0.54°C to 36.79°C and decreases the temperature standard deviation to 0.52°C. Furthermore, this configuration achieves an 18% reduction in pressure drop, while the heat taken away by the coolant and the comprehensive performance evaluation factor increase by 3% and 15%, respectively. These findings provide a quantitative basis for designing high-efficiency liquid cooling plates.