Liquid-immersed thermal management to cylindrical lithium-ion batteries for their pack applications

Immersed thermal management shows distinct advantages while cooling the lithium-ion battery modules. This work conducts numerical-experimental studies to analyze the significance of optimizing system configurations and operational modes by using immersion thermal management. Numerically and experimentally, the effects of batteries' staggered distance, reciprocating flow period of immersion liquid, immersion ratio, as well as the volume flow rate of immersion liquid on battery thermal performances are investigated. The findings indicate that the optimal cooling performance is achieved when the staggered distance equals half the distance between the centers of adjacent cells on the same column (15.5 mm). In this arrangement, the impact of the reciprocating flow period of the immersion liquid on the cooling performance of the system is negligible. Likewise, the best cooling effect is also achieved when the batteries are completely immersed (immersion ratio of 1). Increasing the volume flow rate positively influences diminishing batteries temperature rise and difference, albeit with marginal effects in this configuration. Subsequently, the numerical simulation results are validated through experiment, revealing a maximum deviation of 1.18 °C between the simulation and experiment. The results of the study will be able to serve as a technical reference for researchers to design an efficient battery thermal management system (BTMS).