Keywords: 
• lithium-ion battery /
• thermal runaway /
• thermal runaway propagation /
• energy storage /
• safety

Abstract: In this paper，the thermal runaway and its propagation behaviors of 42 A?h prismatic lithium-ion battery with LiNi1/3Co1/3Mn1/3O2 cathode for electric vehicles are studied under thermal abuse on cell and module level. The results indicate that the maximum temperature is close to 1000℃ inside the cell, with a maximum temperature difference up to 450℃ within the cell during thermal runaway. The thermal runaway propagation time within a lithium-ion battery is 8-12s under 100%SOC. The temperature characteristics of lithium-ion battery have large difference for thermal runaway propagation test and adiabatic thermal runaway test. In a propagation test ,the thermal runaway initiates from a forward surface toward the failure point, whereas thermal runaway occurs simultaneously in the cell under adiabatic test. More than 80% particles vented from the cell are LiF and graphite during the adiabatic test. Approximately 90% of the heat released by the thermal runaway is used for heating the residual and venting particle of the cell. The study guidance reference for the safety design the mitigation strategy of thermal runaway propagation in lithium-ion battery modules, and the accident investigation for new energy vehicle.