Improving the electro-thermal performance of battery module using a pulse liquid immersion cooling strategy

As electric vehicles advance, maintaining the lithium-ion batteries’ performance and safety has become more crucial. To confront this challenge, a liquid immersion battery cooling system employing flow guides with fish-shaped holes based on an innovative pulse control technique is developed. The battery modules’ electro-thermal performance and overall heat transfer performance are investigated through both experimental and numerical approaches. The effects of different flow guides and pulse control methods on the temperature variation, voltage equalization and pumping cost under different operating conditions are analyzed systematically. Compared to other flow guide designs, the battery module using flow guides with fish-shaped holes exhibits better cooling performance and electro-thermal equalization behavior, with maximum reductions in maximum temperature, maximum temperature difference, pumping cost and voltage deviation of 4.9%, 8.9%, 48.8% and 10.3%, respectively. Additionally, the liquid immersion battery cooling system employing the multi-inlet coordinated staggered pulse control method has an advantage in temperature regulation and voltage equalization over the traditional synchronous pulse control method, particularly at a 50% output ratio. Under an equivalent average flow rate, the multi-inlet coordinated staggered pulse control method not only improves thermal stability and cooling performance but also enhances the battery pack’s equalization performance and overall heat transfer performance, especially at a 25% output ratio. Moreover, $1 per m3 invested generates approximately 15.7 W for the proposed battery thermal management system, while for the Tesla Model S, it generates about 15 W. Compared with the Tesla Model S, the proposed BTMS has better compactness and cost-effectiveness.