Large-scale zone-based approach to global modeling and optimization for a novel thermal management system of module-free lithium-ion battery

Urgent need for driving range of lightweight electric vehicles has given birth to module-free lithium-ion batteries with high efficiency and low costs. Conventional module-based design methodology is not suitable for module-free battery thermal management systems (MF-BTMS). In this study, zone-based modeling and optimization approach is proposed for MF-BTMSs, which consists of zone definition, zone connection and pack-level optimization. Using this approach, with temperature uniformity and energy efficiency taken into consideration, a novel air-cooling MF-BTMS with heat pipe group and phase change materials (HPG-PCM) is designed. It is applied to batteries with different scales to study the effects of in-ventilation fin spacings and air-velocity under ambient temperature. It is found that with zone-based model, the in-pack predicted temperature error does not exceed 3% on average. Comparing to the conventional one, this method improves in-pack temperature uniformity 50.79% on average, and the highest value is 93.28%. Meanwhile, the energy consumption for cooling systems can be saved by 61.71%, which will extend the cruise range. It is also proved that air-cooling HPG-PCM system can be effective for MF-BTMSs, as the heat dissipation performance is enhanced with the assistance of cooling fins, while in-pack temperature maldistribution is reduced by adjusting fin spacings.

Automated summary

A zone-based modeling and optimization approach is proposed for module-free battery thermal management systems, leading to improved temperature uniformity, energy efficiency, and reduced energy consumption for cooling systems. Adjusting fin spacings to optimize heat dissipation performance and reduce temperature maldistribution within the batteries is effective in enhancing the overall system performance.