Hybrid cooling approach using PCM and liquid cold plate for battery thermal management of cylindrical cells

Purpose This study aims to present a computational investigation of a hybrid battery thermal management system (BTMS) that combines phase change material (PCM) with liquid cooling for lithium-ion battery cells. Effective thermal regulation is crucial for ensuring safety and performance, particularly under high charge and discharge rates that generate significant heat. Design/methodology/approach A three-dimensional transient CFD model was developed in ANSYS Fluent using the enthalpy porosity method to simulate the melting behaviour of n-eicosane PCM and forced convection within a copper and aluminium cold plate. A Panasonic NCR18650PF cylindrical cell with a capacity of 2.4 Ah and nominal voltage of 3.6 V was modelled as a uniform heat source producing 94,023.8 W/m³ at a 3C discharge rate. Different BTMS configurations were analysed to evaluate temperature rise, temperature distribution and uniformity. Findings The hybrid configuration effectively reduced the maximum temperature compared to standalone liquid cooling. At ambient temperatures of 300 K and 305 K, the 50% PCM coverage reduced peak temperatures from 338.21 K to 306.24 K and from 343.21 K to 310.50 K, corresponding to reductions of 9.3% and 9.5%. The temperature uniformity index (TUI) also improved significantly, decreasing from 3.42% and 3.26% to 0.46% and 0.40%. In a four-cell arrangement using the same PCM design, comparable performance was observed with TUI values of 0.57% and 0.42%, and PCM melting began at 425 s, indicating strong scalability. Originality/value These results demonstrate that the hybrid PCM and liquid cooling approach offer an efficient and scalable solution for managing thermal conditions in cylindrical battery cells used in electric vehicles.