Explosion-venting overpressure structures and hazards of lithium-ion batteries thermal runaway gas induced by multiple vents of energy storage system container

With the rapid development of the electrochemical energy storage industry, energy storage system containers are widely used as a new facility for loading and transporting lithium-ion batteries and devices. To comprehensively understand the thermal runaway explosion hazards associated with lithium-ion batteries in the container, a three-dimensional simulation model incorporating multiple vent structures was developed. Fascinating numerical analysis was conducted to study the explosion-venting overpressure risks resulting from the interaction between the battery obstacle and the vent structure. The results indicated that various regions inside the container exhibited explosion-venting overpressure structures characterized by ‘single-peak’, ‘double-peak’, and ‘three-peak’ configurations composed of peaks P_b, P_cv, and P_mfa, respectively. In the center and at both ends of the container, the peak P_mfa and peak P_cv emerged as the predominant features of the overpressure structure, exerting a significant influence on the explosion disaster. The ‘three-peak’ structure outside the container was primarily influenced by the maximum external explosion overpressure peak P_ee. When one end of the container was ignited, the peak P_ee at the opposite end became more pronounced and exhibited hysteresis. The real hazard of explosion-venting dynamic pressure came from the energy accumulation. The occurrence of external explosion further delayed the downward of dynamic pressure outside the container, thus expanding the dynamic pressure hazard range.