Experimental Study on Thermal Management of Nano-Enhanced Phase Change Material Integrated Battery Pack

Abstract In recent years, lithium-ion batteries (LIBs) have gained attention and popularity due to their extended cycle life and high energy density. A hexagon-shaped 18,650 lithium-ion cylindrical cell battery pack was designed, incorporating paraffin wax (PA) as a phase change material (PCM) and nano-enhanced phase change material (Ne-PCM). However, the low thermal conductivity of the PCM causes a significant challenge to the development of electric vehicles (EVs). The highest temperature in the cylindrical cell battery pack is reached in the midregion, leading to an uneven temperature distribution across the cells. To overcome these challenges and achieve efficient battery module performance, phase change with nanomaterials such as graphene platelet nanopowder (GPN), multiwalled carbon nanotubes (MWCNTs), and graphite-synthetic powder (GSP) was placed in the center of four cells. Studies on the battery module were conducted without cooling, with PCM cooling, and with Ne-PCM cooling. The investigation revealed that the battery pack with Ne-PCM performed well, maintaining the temperature below 50 °C at different discharge rates of 1C, 2C, and 3C, and ensuring a uniform temperature variation within the cells. Ne-PCM decreased the temperature differential between the modules at 1C, 2C, and 3C discharge rates by 85.49%, 91.47%, and 84.21%, respectively, compared to PCM.