In this work, a numerical optimisation process is applied to improve the fluid dynamical aspect of an innovative direct liquid cooling strategy for lithium-ion–based HEV/EV. First, the thermofluidic numerical model of the battery cell defined by means of CFD computational tools was validated with experimental tests. Then, a comparison between different flow patterns was developed to analyse the influence of the fluid distribution geometry. Finally, a parametric multi-objective optimisation process was implemented arranged by a two-level full factorial design. Considering as input variables the height of the fluid, the number of cooling channels, the number of distributors, and the flow rate, the optimal relationship between the thermal performance of the battery cell, the volumetric energy density of the system, and the power consumption of the strategy was obtained. As a result, the energy density of the system was maximised, and the power consumption was reduced while keeping the cell temperature within the optimal range.

This study presents an experimental assessment of how thermal management strategies influence the degradation kinetics of lithium-ion battery modules. To enhance temperature control at the system level, a novel partial Direct Liquid Cooling (DLC) configuration was developed, establishing direct physical contact between the cell surfaces and a dielectric fluid. The efficacy of the proposed DLC design in mitigating battery aging was validated through a rigorous comparative analysis against conventional Indirect Liquid Cooling (ILC), the current benchmark technology in electric vehicles. The experimental data demonstrate that the proposed partial DLC strategy significantly enhances the battery system’s thermal control, maintaining it within the optimal temperature range under identical electrothermal stress. Apart from providing higher thermal management control than conventional strategies, linear extrapolation of the measured capacity-fade trends indicates a projected increase in battery durability of 67.4%, highlighting the potential of the proposed partial DLC strategy to substantially extend system lifespan and withstand extreme operating conditions. Furthermore, while the ILC subsystem exhibited severe degradation with a 24% increase in internal resistance, the proposed partial DLC system remained remarkably resilient, retaining a stable resistance profile. These findings validate the technical viability of the proposed partial direct liquid cooling strategy as a high-performance thermal management solution for e-mobility applications.

Lithium-ion batteries are being used everywhere in a great variety of applications. There are some mayor applications such as the ones related to road transportation which have consolidated and well-known standards and regulations to guide battery designers. Nonetheless, the design standards and regulations of battery systems for non-common applications such as off-road vehicles, maritime type vessels or stationary applications are either generic from road transportation applications or simply unknown. Consequently, a study of standards for non-common three use cases has been performed. The performed study collects and classifies the most interesting standards that will guide battery system and sub-system designers on the development of battery systems for off-road use cases, marine use cases and stationary use cases. In addition to this, representative electric power profiles for each of these three non-common use cases are presented as alternatives to he well-stablished standardized driving cycles. As result, a list of standards that will guide battery system and sub-system designers have been provided along with a driving cycle that captures properly the characteristics electrical stresses of each of these non-common applications.