Experimental Investigation on Single-Phase Immersion Cooling of a Lithium-Ion Pouch-Type Battery under Various Operating Conditions

The selection of a battery thermal management technique is important to overcoming safety and performance problems by maintaining the temperature of batteries within a desired range. In this study, a LiFePO4 (LFP) pouch-type battery having a capacity of 20 Ah was experimentally cooled with both air and liquid (immersion cooling) techniques. Distilled water was selected as the immersion fluid in the experiments, and the impact of discharge rate (1-4C), immersion ratio (50-100%), and coolant fluid inlet temperature (15-25 degrees C) on the battery temperature were investigated during the discharge period. The experiments revealed that maximum temperatures were reached at approximately 45 degrees C and 33 degrees C for air and distilled water cooling techniques, respectively, at the discharge rate of 4C. The average and maximum battery surface temperatures can be reduced by 28% and 25%, respectively, with the implementation of the liquid immersion technique at the discharge rate of 4C compared to the air technique. Moreover, the experiments demonstrated that the maximum temperature difference could be lowered to 4 degrees C by means of 100% liquid immersion cooling at the highest discharge rate, where they are approximately 11 degrees C and 12 degrees C for air and 50% for immersion cooling, respectively. In addition, it was observed that the coolant fluid inlet temperature has a significant impact on battery temperature for %100 liquid immersion.

Automated summary

In this study, the performance of a LiFePO4 pouch-type battery using air and liquid (immersion cooling) techniques was investigated. The results showed that the liquid immersion technique can reduce the battery temperature by 28% at a discharge rate of 4C. Furthermore, 100% liquid immersion cooling can lower the maximum temperature difference to 4 degrees Celsius.