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

Abstract

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 °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 °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 °C) pack performed better than Hybrid BTMS with PCM and Liquid Cooling (45 °C) and Inorganic PCM based BTMS (64.20 °C) but performed worst compared to bi-NePCM arrangement (38 °C). All BTMS packs weighed <20 % of bare pack thus, deemed feasible.