Innovative hybrid battery thermal management system incorporating copper foam porous fins and layers with phase change material and liquid cooling

• Hybrid system reduces max battery surface temperature by 9.18 K at 5C discharge rate. • Porous fins improve energy density by 25%, outperforming traditional solid fins. • Innovative design keeps battery pack temperature difference below 1 K across cells. • Porous layers in copper tubes declines max battery surface temperature by 2.4 K. • High porosity porous layers and low porosity fins provide optimal cooling. In the present numerical investigation, a hybrid battery thermal management system (HBTMS) has been studied which combines phase change material (PCM), copper foam as porous fins and porous layers, and liquid cooling. The system includes twelve 18,650 Lithium-ion batteries encased in aluminium housing, with copper foam used as longitudinal porous fins within the PCM and as porous layer inside copper tubes within the cooling plates. The enthalpy-porosity model was employed for PCM simulation, and the Darcy-Brinkman-Forchheimer (DBF) model was used for copper foam. Local thermal equilibrium (LTE) and non-equilibrium (LTNE) models were utilized to simulate the porous fins and layers, respectively. Transient heat generation was considered based on a lumped-capacitance thermal model. This study addresses a key research gap by optimising the properties of porous fins and layers to enhance both passive and active cooling mechanisms, to effectively improve both thermal performance and energy density. The obtained results indicated the superior performance of porous fins compared to solid fins. The proposed HBTMS significantly reduces the maximum battery surface temperature by up to 9.18 K at a 5C discharge rate compared to pure PCM battery thermal management system (BTMS), while maintaining maximum temperature difference within the battery pack below 1 K, even at high 5C discharge rate. While porous fins with lower porosity improves conduction in the PCM, porous layers with higher porosity enhances convection within the copper tubes. Also, the utilization of porous fins, compared to solid fins, improves the energy density of the system by approximately 25 %.