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.

对轻量化电动汽车续航里程的迫切需求催生了高效低成本的无模块锂离子电池。传统的基于模块的设计方法不适用于无模块电池热管理系统 (MF-BTMS)。在这项研究中，提出了基于区域的建模和优化方法，用于 MF-BTMS，包括区域定义、区域连接和包级优化。使用这种方法，在考虑温度均匀性和能源效率的情况下，设计了一种具有热管组和相变材料（HPG-PCM）的新型空冷 MF-BTMS。应用于不同尺度的电池，研究环境温度下通风翅片间距和风速的影响。发现使用基于区域的模型，包装内预测温度误差平均不超过3%。与传统方法相比，该方法平均提高了50.79%的包内温度均匀性，最高值为93.28%。同时，冷却系统能耗可节省61.71%，扩大巡航范围。还证明了风冷 HPG-PCM 系统对 MF-BTMS 是有效的，因为在散热片的帮助下提高了散热性能，同时通过调整散热片间距减少了封装内温度分布不均。