Simultaneous numerical investigation of the passive use of phase-change materials and the active use of a nanofluid inside a rectangular duct in the thermal management of lithium-ion batteries

This paper numerically investigates cooling of a cubic pack of nine cylindrical type lithium-ion batteries. The pack is first equipped with three separate ducts to convey alumina (Al₂O₃)/water nanofluids (NFs), and all the assembly of battery cells and ducts are then dipped in a phase-change material (PCM). Simulations are carried out to investigate the effects of parameters including the volume fraction of nanoparticles (NPs) and the height of the ducts. The study is transiently performed in the time course of 0–60000 s to scrutinize the temperature of batteries and the nanofluid, the volume of molten PCM, and the heat transfer coefficient (U-value) in both PCM and nanofluid. Within the time courses studied, a maximum of 67.5% of PCM is transformed into the liquid. An increase in the height of the ducts diminishes the maximum temperature and the average temperature of the battery cells and inflated the temperature of the output nanofluid. The maximum heat transfer coefficient in the nanofluid is observed at the 20 mm height at 47th min, followed by the 12 mm height of the ducts. A raise in the duct height increases the U-value in the PCM in a continuous manner.