Experimental study on thermal management of batteries based on the coupling of metal foam-paraffin composite phase change materials and air cooling

With the development of electric vehicles, it is particularly important to develop an efficient battery thermal management (BTM) system to control the temperature of lithium batteries within the safe range. In this study, the heat production characteristics of square lithium iron phosphate batteries were studied, and phase change materials (PCMs) were applied to the thermal management of lithium batteries. The results show that the surface temperature of the lithium battery is higher near the electrode and lower away from the electrode, and the temperature increases with the increase of ambient temperature and discharge rate. In addition, copper-foam paraffin can reduce the battery surface temperature to 46.9 °C, which is 4.1 °C lower than pure paraffin. On this basis, according to the heat generation characteristics of the battery, the battery pack with air-cooled channel was designed to reduce the weight of PCM and accelerate the regeneration of PCM, which is conducive to the development of the endurance of electric vehicles. The experimental results show that the coupling of PCM cooling and air cooling has better thermal management effect. When the wind speed is 30 km/h, the maximum surface temperature of the battery is 43.0 °C, which is 3.9 °C lower than that of only PCM cooling, and the higher the wind speed, the lower the surface temperature of the battery. When the battery is fully discharged, the surface temperature of the battery can be reduced to 35 °C in only 80 min in the natural state.