A numerical study on the battery thermal management system with mini-channel cold plate considering battery aging effect

Abstract

Battery aging is critical for the batteries in electric vehicles, significantly affecting both thermal characteristics and electrochemical performance. In this research, a more realistic and generic model combining the electrochemistry, capacity fade and heat transfer is developed for the design of battery thermal management system (BTMS) to ensure efficient and durable operation of batteries. The thermal behaviors and electrochemical characteristics in different working cycles of BTMSs with X direction and Y direction mini-channels are analyzed and compared. It is found that BTMSs only provide effective cooling to batteries in their initial working cycles but fail to control the battery temperature after 1000 cycles due to the higher heat generation rate of aged battery caused by solid electrolyte interphase (SEI) formation. In addition, BTMS with Y direction mini-channels always provides more effective cooling to batteries to achieve good electrochemical performance with acceptable higher pressure loss during battery cycling. Furthermore, the optimization schemes are proposed for BTMS with Y direction mini-channels to further enhance cooling of the battery for high performance and durable operation of the batteries. The results show that optimizing mini-channel arrangement, arranging circular pin fins (CPF) and dispersing nanoparticles into coolant can be helpful for BTMS to provide effective thermal manage, achieve higher average potential and prevent SEI formation and capacity fade even after 1000 cycles, although the pressure loss is also higher.