Abstract:  In order to investigate the effectiveness of low-pressure and low-oxygen environment in high altitude airport on the parameters of jet flame temperature, heat release rate and flue gas composition in the thermal runaway behavior of lithium-ion batteries, the low-pressure test platform of lithium-ion battery was established to simulate the thermal runaway in high altitude airport (50 kPa) and plain airport (90 kPa) respectively. Four 18650 lithium-ion batteries were used as the experimental objects. The results showed that under the condition of 50 kPa, the damage degree of the cell, the heat release rate and the temperature of the jet flame decreases, among which the peak temperature of the jet flame reduces by about 241.3 ℃. Under the condition of 50 kPa, the concentration offlammable gases like C_xH_y and CO in the pyrolysis flue gas is higher, the highest concentration can reach 3 134.50×10^-6 and 0.860% respectively, which increases with the increase of heat release rate.Under the condition of 90 kPa, the concentration of C_xH_y and CO decreases, which decreases with the increase of heat release rate. The combustion and explosion of the batteries is more violent under the condition of 90 kPa. The concentration of CO₂ gas is the proof of the complete combustion of the substance. The highest concentration of CO₂ gas under 90 kPa can reach 1.510 7% and it is higher than that under 50 kPa.

Key words: high plateau airport, low pressure, lithium-ion battery, thermal runaway, C_xH_y