An improved mini-channel based liquid cooling strategy of prismatic LiFePO4 batteries for electric or hybrid vehicles

Abstract

Li-ion batteries are one of the most widely used energy storage devices owing to their relatively high energy density and power, yet they confront heating issues that lead to electrolyte fire and thermal runaway, especially in automotive applications. A well-designed thermal management system is necessary to mitigate the thermal issues occurring in high charge/discharge conditions. Keeping this in view, an ingeniously designed rectangular mini-channel cold plate is proposed to sandwich in between two consecutive 7Ah prismatic lithium iron phosphate (LiFePO4) batteries with a provision of coolant flow through the mini-channels across the cold plate to form a battery module. A numerical model for the varying channel number, channel width, coolant flow rate, coolant and ambient temperature, etc. to uphold the battery module temperature within the range of 25 °C-40 °C is developed in COMSOL Multiphysics 5.4. A detailed thermodynamic analysis suggests that a cold plate comprising 5 mini channels of width 4 mm with parallel flow design, and water entry near to the charging port with a flow rate of 0.003 kg.s − 1 and temperature of 25 °C as the ideal trade-off between heat transfer and pressure drop for better thermal management across the battery module. A uniform heat propagation in longitudinal direction justifies the optimum design of the cold plate.