Simulation study on thermal management system of battery module with dual bionic cold plate structure

The thermal safety of high-capacity lithium iron phosphate (LiFePO4) batteries becomes increasingly critical under normal-rate discharge conditions. Their optimal operating temperature window is merely 20–40°C, and the inter-cell temperature difference must be strictly maintained within 5°C. Inspired by the efficient transport characteristics of pine branches and the space-saving hexagonal architecture of honeycombs, this study proposes a novel Dual Bionic Cold Plate (DBCP). Four composite channel configurations (D1–D4) were designed and evaluated. Results indicate that the dual-inlet dual-outlet structure (D3) achieves the best cooling performance. Subsequently, the Box–Behnken Response Surface Methodology (RSM) was employed to optimize three critical geometric parameters: honeycomb block diameter, main/secondary channel width ratio, and number of main channels. The optimal configuration – block diameter of 15 mm, width ratio of 1.5, and four main channels – reduces the maximum temperature (Tmax) to 33.99°C and the temperature difference (ΔT) to 4.3°C under 25°C ambient and 1C discharge conditions (where 1C corresponds to a current that fully charges or discharges the cell in 1 hr). This study demonstrates that, compared with a conventional straight-flow cold plate of the same volume, the optimized dual-biomimetic composite cold plate (DBCP) reduces the maximum battery temperature by 0.98°C and decreases temperature non-uniformity by 22.65%. These results confirm that the dual-biomimetic composite structure effectively enhances heat dissipation efficiency and temperature uniformity, providing a practical reference for the thermal management of large-capacity lithium iron phosphate battery modules in electric vehicles.