Parametric liquid-cooling design for Li-ion batteries based on flow regime analysis

This study presents a computational fluid dynamics (CFD) model to predict transient temperature distributions in a prismatic lithium‑ion polymer (LiPo) battery cooled by forced water circulation through four distinct cooling circuits during constant‑current discharge. A novel methodology emphasizes the influence of dimensionless parameters on thermal and electrical responses, addressing a gap in existing literature and improving understanding of battery cooling strategies. The cooling circuit is modeled as a recirculating system, reflecting practical implementations rather than the common open‑loop assumption, and capturing the additional instability and complexity inherent to recirculation. Transient electrochemical–thermal behavior is simulated using Newman’s pseudo‑2D approach, treating porous electrodes as a collection of equal‑sized, isotropic, homogeneous spherical particles. The model couples electrochemical dynamics with conjugate heat transfer in the cell and cooling circuit. Validation was performed in a controlled chamber using experimental measurements and infrared thermography during discharge; simulated temperature, state of charge, and voltage curves were compared against experimental data. Results show strong agreement between simulations and experiments, demonstrating the model’s reliability for predicting LiPo battery behavior and their cooling circuits. Key battery parameters — effective capacity, specific energy density, specific heat capacity, electrical conductivity, and specific thermal capacity — were carefully estimated and validated to provide reliable reference values for modeling batteries of the same type. By systematically analyzing the role of relevant parameters —temperature, Reynolds number, flow velocity, heat flux, and pressure— on battery–cooling interactions, the model analyses their relative effects and provides actionable guidance for optimizing thermal management strategies in battery applications. This research provides practical value for battery designers and engineers developing systems that integrate batteries, facilitating improved efficiency, performance and safety.