Experimental study on the characteristics of thermal runaway propagation process of cylindrical lithium-ion batteries

This study examines the risks of thermal runaway in Lithium-ion batteries, especially under abusive conditions, which can lead to high temperatures, combustion, and explosions, posing safety threats. It focuses on thermal runaway propagation, temperature changes, propagation time, mass alterations, gas composition, and concentration shifts. Experiments were conducted on various Lithium-ion batteries with different SOCs. The results show inevitable thermal runaway in one-dimensionally arranged cylindrical Li-ion batteries. Higher SOC batteries have increased combustion risks, faster transfer rates, longer gas release, and produce irritating gases like NH3, HCl, and HF. Trigger temperatures and times vary with SOC: 100% SOC batteries trigger at 97°C in 185 s, while 25% SOC batteries trigger at 232°C in 299 s. The propagation time between adjacent batteries decreases from 273 s to 74 s as SOC increases from 25% to 100%. A predictive model is introduced to calculate peak temperatures and analyze propagation paths, enhancing understanding and safety considerations of thermal runaway in batteries.