The objective of this study is to numerically investigate the battery thermal management of electric vehicles using phase change material. The lithium-ion batteries which are widely used in electric vehicles have an optimal operating temperature range from 25°C to 60°C, above which the battery does not operate effectively. There are various cooling methods such as active cooling method and passive cooling method. The present study is based on passive cooling method where the thermal performance of different phase change materials such as paraffin wax, extended graphene and capric acid are compared for different heat source intensities. The numerical simulation is performed using Ansys Fluent by considering the melting and solidification effects of the phase change materials. The investigation is performed by varying the thermo physical properties of the phase change materials and temperature of the battery packs. The results are analysed by plotting the temperature and velocity contours and the melting and heat transfer rates of different phase change materials are also compared. The results from the present study would be useful in identifying the ideal phase change material with improved thermal performance characteristics. © Published under licence by IOP Publishing Ltd.