关键词: 锂离子电池, 荷电状态, 热失控, 反应动力学, 破坏半径

Abstract: Taking the high specific energy 18650 lithium-ion battery as the research object， using adiabatic accelerated calorimetry to carry out thermal runaway experiments on lithium batteries with different SOC，calculating the reaction kinetic parameters during the thermal runaway process，and finally analyzing the destructive nature of the battery thermal runaway. The results showed a risk of thermal runaway when the SOC ≥ 25%，and the larger the SOC，the shorter the trigger time of thermal runaway. The reaction kinetics calculations showed that the activation energy and preexponential factor decreased with increasing SOC. The thermal runaway release energy，TNT equivalent，and damage radius increased with increasing SOC. It indicates that batteries with high SOC are thermally unstable and more prone to thermal runaway.

Key words: lithium-ion battery, the state of charge, thermal runaway, reaction kinetics, damage radius