In this research, a combined cooling method is used for the thermal management of lithium-ion batteries. This cooling method is combination of the flow boiling cooling via flow boiling through half-helical tubes wrapped around batteries with the air-cooling method via air flow passing through the batteries. The numerical modeling has been carried out using control volume technique and the used model for modeling the flow boiling region is Eulerian-Eulerian multiphase model. The obtained results showed that the proposed combined cooling method contributes to better thermal management of the battery pack. The occurrence of flow boiling inside the helical tubes contributes to considerable heat removal due to latent heat of vaporization at a constant temperature and the battery temperature remains almost constant in the parts of batteries that are in contact with the boiling fluid. Increase of the mass flux of the boiling fluid and inlet air velocity reduces the maximum temperature over the batteries inside the battery pack. Besides, by decreasing the inlet subcooling of the boiling fluid, the temperatures of the batteries are reduced and the temperature difference between the batteries in different rows of the battery pack is less affected by the air inlet velocity.
