A Compact Hybrid Battery Thermal Management System for Enhanced Cooling

Hybrid battery thermal management systems (HBTMS) that combine active liquid cooling and passive phase change materials (PCM) have demonstrated significant potential for managing the thermal characteristics of lithium-ion batteries. Nevertheless, the volume of coolant and PCM is constrained by the size and weight of the HBTMS during high charge/discharge rates, which negatively impacts convective heat transfer during battery discharge. This study investigates a compact hybrid cooling system featuring multi-inlet U-shaped microchannels embedded with PCM/aluminum foam, enhancing system compactness. Utilizing nanofluid cooling technology improves thermal conductivity, while a newly developed pulsed flow function further optimizes cooling efficiency with reduced power requirements. An experimentally validated thermal-fluid dynamics model is employed to fine-tune operating conditions, such as coolant type and channel characteristics. Results indicate that the proposed hybrid cooling solution significantly lowers the maximum temperature of the lithium-ion battery by 3.44°C during a 1C discharge at room temperature (25°C) with only a marginal 5% increase in power consumption, compared to conventional cooling methods used in electric vehicles (EV). Additionally, the average battery charging capacity increased by approximately 6 to 15 percent, suggesting that the findings can enhance both the range and safety of new energy EVs.