Critical conditions for the thermal runaway propagation of lithium-ion batteries in air and argon environments

Thermal runaway (TR) propagation of lithium-ion batteries (LIBs) in air may cause fire, and argon can effectively inhibit LIBs with TR propagation. The oxygen concentration and gas flow rate are the important factors affecting the TR propagation. Hence, an experimental device for LIBs with TR propagation in air and argon environments in a confined space was established, and a series of experiments were carried out. Subsequently, the critical conditions of oxygen concentration and gas flow rate that inhibit the TR propagation of the cell are investigated. The study found that LIBs with TR propagation occur in an air environment, while argon gas has a good effect on inhibiting LIBs with TR propagation. The critical oxygen concentration for LIBs with TR propagation in an argon environment is between 2.5 and 5%. The critical gas flow rates for LIBs with TR propagation are greater than 24 L min⁻¹ under air and are between 18 and 24 L min⁻¹ under argon. It is firmly believed that this work can provide useful inspirations for the TR suppression of LIBs.