Channel structure design and optimization for immersion cooling system of lithium-ion batteries

Abstract

The phenomenon of heat accumulation during the discharge process of lithium-ion batteries (LIBs) significantly impacts their performance, lifespan, and safety. A well-designed cooling architecture is a critical issue for solving the heat accumulation problem of the battery immersion cooling system (BICS). In this study, four cooling channel design schemes (CC-1, CC-2, CC-3, and CC-4) for the BICS were developed. The effect of various cooling channel structures on the cooling performance of BICS has been studied. Comparative analysis reveals that the CC-1 structure demonstrates the most outstanding overall performance. It effectively manages battery pack temperatures while maintaining temperature uniformity, and its pressure drop remains comparable to other designs. Applying orthogonal analysis, the CC-1 structure was further optimized. Subsequently, a linear weighting method was employed to analyze multiple evaluation indexes comprehensively. The following optimal structural parameters were obtained: battery spacing (S) of 4 mm, baffle height (H) of 42 mm, distance from the inlet to the channel bottom (L) of 14 mm, and a coolant mass flow rate (Q) of 0.04 kg/s. Compared to before optimization, the battery pack's maximum temperature and temperature difference have been diminished by 17.9 % and 20.8 %.