Benign-to-malignant transition in external short circuiting of lithium-ion batteries

Abstract

External short circuiting (ESC) is a main source of battery faults. However, the ESC damage mechanism and its evolution process are unclear, resulting in difficulties in safety management. Here, we report the impact of different ESC durations on battery performance and divide the ESC process into four stages. The analysis reveals that there is a benign regime in which the ESC effect is comparable to nominal charge-discharge cycling. When ESC duration is close to a critical time, there is a benign-to-malignant transition. The critical time corresponds to the inflection point at the end of battery current curve, which reflects heating-induced membrane melting and contraction that distorts the jellyroll. The critical time surface under various conditions is established and the center temperatures of the critical time and battery completely failure are disclosed, paving the way for fault diagnosis and using “benign ESC” in a controlled fashion. • Benign-to-malignant evolution of battery ESC damage mechanism is revealed • Critical time to characterize the occurrence of malignant battery damage is identified • Equivalent influence correlation is established between benign SC and nominal cycling • Battery heating method based on controllable benign short circuit is proposed Chen et al. reveal the evolution of damage mechanism during battery external short circuit, pointing out that there is a benign-to-malignant transition. The critical time to characterize the battery malignant damage is identified. This research may open new possibilities for applying short circuit in a controlled fashion.