Enhanced thermal management of lithium-ion batteries using hybrid nanofluids in finned mini-channels: Energy and entropy analyses

Efficient thermal management is crucial for maintaining the safety and lifespan of battery packs, particularly during high-discharge operations. This study investigates an innovative approach to cooling these batteries by modifying traditional rectangular mini-channels with bio-inspired fins, modeled after dolphin dorsal shapes and fish contours. Unlike conventional cooling designs, these structures enhance fluid mixing and heat transfer efficiency when paired with a hybrid nanofluid (Fe 3 O 4 –SWCNT in water) under laminar flow conditions. A time-dependent numerical simulation was conducted to replicate unsteady heat generation in battery cells, and the results were validated against established studies. The findings indicated that dolphin dorsal fins and fish-shaped fins reduce total entropy generation by 28.59 % and 14.12 %, respectively, compared to a standard mini-channel. Additionally, the convective heat transfer coefficient improved by 20.18 % with dolphin fins and 43.04 % with fish fins, demonstrating superior thermal regulation. The hydrothermal performance, evaluated using the performance evaluation criterion (PEC), showed that the fish-shaped fins outperformed dolphin fins by 42.87 %, achieving a PEC value of 1.12. These results highlight the effectiveness of bio-inspired fin geometries in optimizing battery cooling systems, offering a promising strategy for improving the efficiency and longevity of batteries in electric vehicles.