Topology Optimization and Dynamic Heat Transfer Mechanism of Liquid Cold Plates for Lithium-Ion Battery Thermal Management

Aiming to mitigate the issues of heat buildup and excessive flow resistance in traditional cold plates applied to lithium-ion batteries, this work develops a topology optimization framework and produces two optimized layouts (Case III and Case IV) with differentiated multi-objective weight assignments. Their thermo-hydraulic performances were systematically evaluated against parallel (Case I) and serpentine (Case II) channels under various inlet velocities, coolant temperatures, and discharge rates. The results indicate that biomimetic bifurcations in topological channels effectively significantly reduce the extent of low-velocity regions and equalize flow distribution. Among all configurations, Case IV demonstrates the best overall performance: under a 1C discharging rate with an inlet flow velocity of 0.2 m/s, it achieves the lowest maximum temperature (28.97 °C), minimal temperature differential (3.97 °C), and lowest equivalent thermal resistance (0.305 °C/W), while reducing the hydraulic pressure drop by approximately 79.3% (from 436.83 Pa to 90.57 Pa) compared to serpentine channels (Case II). The analyses reveal that increasing inlet velocity beyond 0.3 m/s yields diminishing cooling returns due to internal conductive bottlenecks. Variations in inlet temperature exert negligible impacts on thermal resistance, whereas resistance across discharge rates follows Rth,2C > Rth,3C > Rth,1C > Rth,0.5C, governing transient thermal transport characteristics during high-rate discharge.