Study on the influence of high rate charge and discharge on thermal runaway behavior of lithium-ion battery

With the development of the new energy industry, battery life and rapid charge-discharge capacity have attracted much attention. At the same time, the high temperature inside the cell during high-rate charging and discharging may increase the probability of the battery thermal runaway. This paper studied the thermal runaway reaction of Li-ion batteries under different state of charge (SOC) and charge rates using a self-made experimental platform. The experimental phenomena and the changes in the temperature field were recorded. The key parameters, such as trigger temperature (T_1, Lithium battery back thermal runaway triggers temperature), maximum temperature (T_max),voltage, and mass loss (ML) of thermal runaway, were measured. The morphology changes of electrode materials, the battery remains, and the dynamics of thermal runaway reaction after high rate charge and discharge were further analyzed. The results show that for the 4 C-100 % battery, the T₁ and E_a are reduced by 22.6 ℃ and 82.2 %, and the T_max and maximum mass loss rate (MLR_max) are increased by 218.14 ℃ and five times, compared with the 1 C-50 % battery. With the increase of charge-discharge rate, the thermal stability of the battery decreases, and the gravity degree of accident increases.