Pressure Effect on the Thermal Runaway Behaviors of Lithium-Ion Battery in Confined Space

As an advanced energy storage medium, lithium-ion batteries (LIBs) are being used in aircraft and other aviation fields owing their unique advantages. The thermal runaway (TR) behaviours of LIBs used in aircraft are more complicated and dangerous due to the special operating environments, such as low pressure and enclosed environments. Therefore, a special test platform was designed to study the effect of low pressure on the TR characteristics of 2.2 Ah 18,650 type LIBs in this work. Some critical parameters of TR were obtained, such as onset temperature of TR, maximum temperature, voltage drop time, pressure, and the explosion limit of gases, etc. The results show that with the pressure increasing, the TR onset temperature, maximum temperature, and pressure increase in the test chamber, and the voltage drop time postpones. In addition, the amount of released gas and the explosion limitation range of gases increase with the decrease of the initial pressure. This means it's easier to occur but with weaker hazard of TR at lower pressure. Besides, the SEM results reveal that deformation and structural damage of cathode materials, which is attributed to the increase of the large amount of gas released at the electrode material level. These results provide the basis for the safe application and storage of LIBs in a confined space under different pressures.