Experimental Analysis of Battery Cell Heating Through Electromagnetic Induction-Based Liquid System Considering Induction Power and Flow Rate Effects in Extreme-Cold Conditions

The performance of lithium-ion batteries deteriorates significantly under extreme-cold conditions due to increased internal resistance and decreased electrochemical activity. This study presents an experimental analysis of a battery thermal management system (BTMS) incorporating electromagnetic induction heating and a fluid-based heat transfer mechanism to alleviate these problems. The experimental setup utilizes a closed-loop circulation system where ethylene glycol-based fluid flows through induction-heated copper tubes, ensuring efficient heat transfer to an 18650-cell battery. This study evaluates heating performance under varying ambient temperatures (-15 degrees C and -5 degrees C), fluid flow rates (0.22, 0.3, and 0.5 L/min), and induction power levels (150 W, 225 W, 275 W, and 400 W). The results indicate that lower flow rates (e.g., 0.22 L/min) provide faster heating due to longer thermal interaction time with the battery; however, localized boiling points were observed at these low flow rates, potentially leading to efficiency losses and thermal instability. At -15 degrees C and 400 W, the battery temperature reached 25 degrees C in 383 s at 0.22 L/min, while at 0.5 L/min, the same temperature was achieved in 463 s. Higher flow rates improved temperature uniformity but slightly reduced heating efficiency due to increased heat dissipation. Internal resistance measurements revealed a substantial decrease as battery temperature increased, further validating the effectiveness of the system. These findings present a viable alternative for heating electric vehicle batteries in sub-zero environments, thereby optimizing battery performance and extending operational lifespan.