Battery Thermal Management of Lithium Prismatic Cell Battery by Using Different Coolants

Abstract

<div class="section abstract"><div class="htmlview paragraph">Lithium (Li)-based batteries have wide applications in the everyday gadgets. Li-based batteries have prominent usage in the automotive sector. All the major OEMs for manufacturing hybrid electric vehicles (HEVs) and electric vehicles (EVs) use only Li batteries and are still going to continue for the next decades. However, during the operation of these batteries, they are susceptible to environmental and battery factors. The amount of charge currently taken in or out influences the internal resistance and temperature of the battery. Therefore, the amount of heat generated by the Li-ion batteries during operation is critical for designing a cost-effective and efficient thermal management system (TMS) for HEVs and EVs. For that, the right cooling mechanism for a lithium-ion (Li-ion) battery pack is to be chosen for the vehicles and establishing optimal cooling conditions to keep the temperature within a safe range of 15 to 35°C, which is critical to improving performance, safety, and life of the battery. For a high-energy Li-ion battery module, this work provides a comparison of air-type and liquid-type thermal management systems. Computational fluid dynamics (CFD) simulations are used to investigate the cooling performance of thermal management systems with different fluids. In this study, the 12 V modules are made up of five prismatic pouch cells and initial constant heat flux is provided for all the cases. The effect of different coolants (i.e., air, water with ethylene glycol, and nano-coolant) at different flow rates and compositions on the module’s thermal behavior are evaluated and compared. Both air and ethylene glycol and water are given a flow rate of 0.5, 1.0, 1.5, and 2.0 m/s, whereas the nano-coolant is given a flow rate of 1.0 m/s. As the nano-coolant flow rate is increased, the Li-ion temperature drops below its optimum range, hence affecting its performance. The results of this research are being put to use in the development of a more effective energy-saving battery temperature management system and in the widespread adoption of nano-coolant for Li batteries. It is observed that the nanofluid gave a superior performance in terms of temperature reduction, that is, 5.04% and 2.97% more efficient than air-cooling and water + ethylene glycol cooling.</div></div>