Numerical investigation of the direct liquid cooling of a fast-charging lithium-ion battery pack in hydrofluoroether

Battery thermal management systems are critically important for ensuring the safety and prolonging the lifetime of lithium-ion batteries in electrical vehicles, especially those under fast charging. In this paper, a novel direct liquid battery cooling system based on a hydrofluoroether (HFE-6120) coolant is proposed for fast-charging battery packs. This paper numerically investigates the critical parameters in direct liquid cooling (DLC) with high-fidelity computational fluid dynamics (CFD) simulations. The results show that the DLC with a full-size channel design and high flow velocity control has a redundant cooling performance with the problems of low energy density and high power consumption, which can be resolved through optimization. First, when designed with a partial height channel and controlled with an appropriate coolant velocity, the mass energy density can be improved by up to 20.3% and the power consumption can be reduced by 95.3% compared to the selected baseline. Second, the maximum temperature difference and temperature standard deviation can be reduced by 18.1% and 25.0%, respectively, with a multilayer structure and cross-flowing configuration. These findings establish an improved understanding of the key parameters of DLC systems and provide guidelines for the design of direct liquid battery cooling.

Automated summary

This paper proposes a novel direct liquid battery cooling system for fast-charging battery packs based on a hydrofluoroether coolant. Through high-fidelity CFD simulations, it is found that optimizing channel design and coolant velocity can improve energy density and reduce power consumption, while a multilayer structure and cross-flowing configuration can reduce temperature difference and standard deviation.