Cai et al. studied the experimental simulation of internal short circuit of lithium-ion battery polymer . They found that the risk of thermal runaway during an internal short circuit increases as the battery’s state of charge (SOC) increases.
External short circuit (ESC) faults pose severe safety risks to lithium-ion battery applications. The ESC process presents electric thermal coupling characteristics and becomes more complex when the batteries operate in large group, which often lead to serious consequences.
Shriram et al. performed a systematic study of the internal short circuit mechanism inside a lithium-ion battery . They found short circuit between lithiated anode material and aluminum current collector, resulting in maximum heat generation.
As a result, when the lithium-ion battery was short-circuited externally, the battery temperature rose rapidly to the maximum temperature that the battery can rise. The highest temperature caused by external short circuit appeared in the case of a single battery. The higher the SOC, the faster the battery temperature rose.
External short circuit would accelerate the rate of increase in internal resistance of lithium-ion battery. Normally, the internal resistance of the battery doubled at approximately 350 cycles. After external resistance, when number of cycle reached 170 times, internal resistance doubled.
Lithium-ion batteries and their modules were subjected to cyclic charge–discharge experiments at different ambient temperatures. External short circuit would greatly reduce the life of lithium-ion battery. In general, the normal battery failure threshold was approximately 350 cycles.