Experimental Investigation of a Battery Thermal Management Device Based on a Composite Phase Change Material Coupled with a Double Helix Liquid Cooling Plate

Phase change materials (PCMs) are considered the most promising cooling technology due to their high latent heat, good reversibility, and low cost. However, in practical applications, PCMs encounter problems such as a sharp temperature increase after full melting and low thermal conductivity. To solve these problems, a new double helix-type liquid cooling plate is developed and coupled with a hydrated salt composite PCM (CPCM) for battery pack cooling. The modified CPCM has a high latent heat (249 J/g), suitable phase change temperature (35 degrees C), improved thermal conductivity to 1.86 W/(m center dot K), and reduced subcooling to 1.9 degrees C. The design of the liquid cooling plate structure can make the average water temperature on both sides of each cell approximate, thereby ensuring the temperature uniformity for the battery pack. A battery module system test rig is constructed and the heat dissipation effect for the battery module is compared with four cooling methods. The results reveal that the CPCM/liquid coupled cooling method is the most effective for cooling the battery pack. At a low coolant flow rate of 0.5 L/min, the maximum temperature difference for the coupled battery module is retained at 1.88 degrees C, and the average temperature is found to increase by only 9.6 degrees C. In addition, different coolant flow rates and control strategies of the coupled heat sink system are tested and compared. An optimal strategy is selected for the cyclic charge/discharge test of the coupled cooling module. The system is found to maintain good cooling performance and temperature uniformity after four charge/discharge cycles, and the highest temperature peak for the battery pack is only 40.3 degrees C, which is within the normal operating temperature range.

Automated summary

Phase change materials (PCMs) are a promising cooling technology with high latent heat, good reversibility, and low cost. A new double helix-type liquid cooling plate is developed and coupled with a modified hydrated salt composite PCM (CPCM) for efficient battery pack cooling. The new cooling method demonstrates high cooling performance and temperature uniformity for the battery pack with reduced subcooling and improved thermal conductivity.