Performance Evaluation of a Novel Coolant Channel Configuration for Liquid-Based Battery Thermal Management in Electric Vehicles

The performance and longevity of lithium-ion (Li-ion) batteries in electric vehicles (EVs) are critically dependent on effective thermal management. As internal heat generation during charge and discharge cycles can lead to uneven temperature distribution, exceeding optimal operating limits (25 - 40°C) can significantly degrade battery performance and lifespan. This study presents a performance evaluation of a novel liquid-based Battery Thermal Management System (BTMS) featuring a dual-directional coolant channel configuration designed to enhance thermal uniformity and heat dissipation. The proposed configuration combines horizontal and vertical coolant passages in an indirect cooling layout to address the limitations of conventional serpentine-type channels. A comprehensive thermal analysis was carried out under realistic loading conditions using three coolant types: water, ethylene glycol-based G48, and graphene-enhanced water nanofluids. These were evaluated for thermal conductivity, heat transfer efficiency, and effectiveness in minimizing temperature gradients. Graphene nanofluids exhibited superior performance due to their high thermal conductivity and enhanced convective heat transfer capabilities. Additionally, the effect of varying coolant flow rates was analysed to simulate different operating scenarios. While increasing flow rates improved cooling effectiveness, the study also identified a threshold beyond which performance gains diminished. The novel dual-channel design demonstrated significant improvements over traditional serpentine configurations, including a notable reduction in maximum cell temperatures and enhanced temperature uniformity across the battery pack. This improvement is critical in reducing hotspots and extending battery health. The dual-directional flow facilitates more efficient convective heat transfer, offering a promising advancement in BTMS design. The integration of advanced nanofluid coolants with an innovative channel configuration pave the way for the development of more efficient, reliable, and thermally stable battery systems in next-generation electric mobility.