Novel Microchannel Based Indirect Liquid Cooling for Lithium-Ion Battery Thermal Management: A 3-D CFD Study

Effective battery pack thermal management is critical in electric vehicle performance optimization. This study evaluates the efficacy of water cooling, utilizing microchannels embedded within an aluminium block, in mitigating thermal run-away within battery packs due to excessive heat generation while charging and discharging. A comparison between rectangular and square cross-section microchannels for varying Reynolds numbers is conducted to determine the optimal geometry for enhanced efficiency. Results indicate that integrating water cooling through aluminium microchannels significantly reduces the battery pack's maximum surface temperatures. It is observed that the rectangular cross-section microchannel with a height of 8 mm exhibited the lowest maximum surface temperature in the range of 335 to 312 K for the range of Reynolds number studied. The same design provided the highest Nusselt number, with the square microchannel giving the least. However, with an increase in microchannel height above 6 mm, the enhancement in Nusselt number is not significant. Microchannel with a height of 4 mm has the minimum friction factor for higher Re, indicating optimal height. Maximum cooling performance is obtained with 8 mm for lower Re; for higher Re, 4 mm performed the best. Hence. If there are no limitations on pumping power, the 4 mm configuration is preferable at higher Re, as it offers superior performance.