随着锂离子电池在高速率工况下的应用日益广泛,热失控(TR)及热失控传播(TRP)等安全性问题变得至关重要。本研究系统探究了高速率循环下电池的TRP动作。微观分析结果表明:经4C循环后正极材料结晶度下降32.95%,负极层状结构受损严重。数据显示,热失控间隔时间(Δ(003)/以4C倍率循环的电池组容量衰减幅度较1C循环组提升83.23%。同时,2#电池的最大质量损失率(ML)增幅达32.35%。我们进一步探究了电池间距对热失控传播(TRP)动作的影响:相较于零间距工况,1.5cm间距下2#电池的最高热失控(TR)温度降低26.21%;当间距从0cm增至1.5cm时,电池组质量损失减少20.73%。研究表明,质量损失率随充电倍率升高而增大,随电池间距扩大而降低。与1C循环的电池相比,4C循环的电池触发热失控(TR)所需的热量显著降低。当间距设置为0、0.6、1.5和2.1 cm时,对应降幅分别可达68.28%、70.10%、76.88%和26.15%。这表明2#电池经历高倍率循环后,仅需极低热量即可进入热失控状态。总体而言,高倍率循环与小间距会加速电池的热失控进程(TRP),并加剧其热失控严重程度。本研究可为储能系统的实际安全设计提供重要参考。(104) of the cathode are decreased by 32.95% and 13.01% after 4 C cycling, while the layered structure of the anode is seriously damaged. As revealed, the TR interval time (Δt) of batteries cycled at 4 C is decreased by 83.23% compared with that for batteries cycled at 1 C. Meanwhile, the maximum mass loss (ML) rate of Battery 2# is increased by 32.35%. We have further investigated the influence of battery spacing on TRP action. The maximum TR temperature of Battery 2# at 1.5 cm spacing is reduced by 26.21% compared with the value at 0 cm spacing. When increasing the spacing from 0 to 1.5 cm, the ML of batteries is reduced by 20.73%. ML increases and decreases with the elevation of the charging rate and battery spacing, respectively. Compared with a battery cycled at 1 C, a battery cycled at 4 C shows reduced heat required to trigger TR. The corresponding decreases can reach 68.28%, 70.10%, 76.88%, and 26.15% when setting the spacing at 0, 0.6, 1.5, and 2.1 cm, respectively. This indicates that Battery 2# can enter TR with much lower heat after high-rate cycling. Overall, high-rate cycling and low spacing accelerate the TRP of the battery and aggravate the TR severity of the battery. This work can provide insights for the practical safety design of energy storage systems.