Optimization of Triple‐Branching Bioinspired Honeycomb Structure Liquid Cooling‐Hydrated Salt Composite Phase Change Coupled Thermal Management Systems for Power Batteries

Effective thermal management is essential for ensuring the performance and safety of lithium‐ion batteries. In this study, a composite phase change material (CPCM)‐liquid cooling coupling battery thermal management system (BTMS) is proposed to suppress heat accumulation and reduce thermal gradients in 18 650 battery packs under high‐rate discharge conditions. An electrochemical–thermal coupling model was established and validated through experiments and multiphysics simulations to predict the spatiotemporal heat generation behavior of the battery. Liquid cooling plates were arranged on the upper and lower surfaces of the module, and the effects of cold plate structure, inlet/outlet configuration, turbulence column radius, channel height, and coolant inlet velocity on thermal performance and pressure drop were systematically investigated. To further improve temperature uniformity, a CPCM composed of calcium chloride hexahydrate and expanded graphite was introduced. Optimal Latin Hypercube Sampling (OLHS), NSGA‐III, and entropy‐weighted TOPSIS were employed for multi‐objective optimization. Under an ambient temperature of 25 °C and a 3C discharge rate, the optimized system achieved a maximum temperature ( T _max ) of 29.49 °C, a temperature difference (Δ T ) of 2.92 °C, and a pressure drop (Δ P ) of 29.83 Pa, reduced by 3.8%, 14.4%, and 74.3%, respectively, compared with the initial BTMS.