Thermal-runaway propagation in battery systems can escalate the battery fire hazard and pose a severe threat to global users. In this work, the thermal-runaway propagation over 18650 cylindrical lithium-ion battery was tested in the linear-arranged module with a 3-mm gap. State of charge (SOCs) from 30% to 100%, ambient temperatures from 20°C to 70°C, and three tab-connection methods were investigated. Results indicate that the battery thermal-runaway propagation speed was about 0.35 ± 0.15 #/min, which increased with SOC and ambient temperature. The critical surface temperature of thermal runaway ranged from 209°C to 245°C, which increased with ambient temperature while decreased with SOC. Compared to the open-circuit module, the flat tab connection could cause an external short circuit to accelerate the thermal-runaway propagation, and the non-flat tab connection was more likely to trigger an explosion. A heat transfer analysis was proposed to qualitatively explain the speed and limiting conditions of thermal-runaway propagation, as well as the influence of SOC, ambient temperature, and tab connection. This work reveals the thermal-runaway propagation characteristics under well-controlled environments, which could provide scientific guidelines to improve the safety of the battery module and reduce battery fire hazards.

中文翻译：

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线性圆柱形电池模块上的热失控传播

电池系统中的热失控传播会加剧电池火灾危险，并对全球用户构成严重威胁。在这项工作中，在具有 3 mm 间隙的线性排列模块中测试了 18650 圆柱形锂离子电池的热失控传播。研究了 30% 至 100% 的充电状态 (SOC)、20°C 至 70°C 的环境温度以及三种接线片连接方法。结果表明，电池热失控传播速度约为 0.35 ± 0.15 #/min，随着 SOC 和环境温度的增加而增加。热失控的临界表面温度范围为 209°C 至 245°C，随环境温度升高而升高，随 SOC 升高而降低。与开路模块相比，扁平接头连接可能导致外部短路加速热失控传播，并且非平片连接更容易引发爆炸。提出了一种传热分析，以定性解释热失控传播的速度和限制条件，以及 SOC、环境温度和接头连接的影响。这项工作揭示了良好控制环境下的热失控传播特性，可为提高电池模块的安全性和减少电池火灾隐患提供科学指导。