A novel approach for active cooling of a battery at cell level: Air-cooled mini-channel heat sink, enhanced with intermittent metal foam

Abstract

Improving the performance and safety of electric vehicles (EVs) requires efficient thermal management of batteries. Although a liquid cooling system with a mini-channel heat sink (MCHS) is an efficient and common approach, it makes the eventual battery pack complex, heavier and expensive. To address this problem, this study proposed the application of air as a coolant for an MCHS by adding intermittent porous zones inside the mini-channel. A numerical study was performed to understand the cooling performance of the mini-channel employed with intermittent porous zones. The results showed that the addition of intermittent porous zones in a mini-channel made the air efficient enough to maintain the battery temperature well below the operating limit at the cell level. However, it was found that the position of porous zones inside the mini-channel significantly impacts the cooling performance. So, a novel approach was proposed for identifying the best locations of porous zones within a mini-channel, and its effectiveness is studied numerically. Results at the cell level showed that the proposed method can give a very close to the optimum solution at the least expense. In this study, the optimum position was found by only 19 simulations among 190 possible choices. The method was applied for cooling a LiPol pouch battery cell. It was shown that filling only 10 % of the min-channel volume with porous blocks can cool the battery as effectively as a fully porous mini-channel. It means a 90 % reduction in pressure drop, fan power consumption and material cost. The maximum observed temperature was 316.7 K for the discharge rate of 3 C.