Experimental investigations of a novel phase change material and nano enhanced phase change material based passive battery thermal management system for Li-ion battery discharged at a high C rate

Increasing energy demand from EVs requires the use of powerful Li-Ion batteries due to their high energy density and low self-discharge. But at high rates of discharge (C rate) Li-Ion batteries exhibit a rise in battery temperature due to which, they can exhibit erosion in their performance. At high temperatures (>50 degrees C), thermal runaway can occur leading to battery fire and explosion thus, eroding consumer confidence. The current study has experimentally investigated a novel Battery Thermal Management System (BTMS) using RT-47 as Phase Change Material (PCM) and enhancing it with gamma-Al2O3 nanoparticles at 0.5, 1, 1.5, 2 and 4 wt% concentrations making Nano-enhanced PCM (NePCM). Five battery packs were assembled based on selected NePCM after characterization i.e., bare, RT-47, 0.5, 1.0, 1.5 wt% NePCM. These packs were subjected to high discharge conditions at 3C discharge rate (12 A current draw) while monitoring their temperature and discharge times. Results showed the maximum temperature of all packs to be approx. 49.3, 43.0, 42.0, 42.0 and 44.0 degrees C respectively. A pack containing 0.5 wt% NePCM performed best with a discharge time of 1113s compared to less than 1000s for all other packs. Thus, 0.5 wt% NePCM based BTMS was selected as the best performer. Comparing the maximum temperature of similar studies, PA05 (43 degrees C) pack performed better than Hybrid BTMS with PCM and Liquid Cooling (45 degrees C) and Inorganic PCM based BTMS (64.20 degrees C) but performed worst compared to bi-NePCM arrangement