## 2 Materials and Methods  
### Study on TR Temperature Characteristics of Cells  
An NCM622 pouch cell (manufactured by Do-Fluoride New Energy Co., Ltd., Jiaozuo, China) with a nominal capacity of 60 Ah was used in the experiment. The detailed specifications are shown in Table 1.  
Before the experiment, a cyclic charge and discharge instrument was used to cyclically pre-treat the battery cell; this process included the following steps. (1) A 0.5 C constant current charge was used to reach 4.3 V. (2) The constant voltage charge was switched until the charging current dropped to 200 mA. (3) The charging was stopped, and the cell was left to stand for 5 min. (4) Constant discharge at 0.5 C was conducted. (5) The above steps were repeated for the pre-cycle treatment of the 2.8 V to 4.3 V voltage range; the process was conducted twice. (6) Finally, the cell was charged to 100% SOC. In the pre-treatment process, it is necessary to ensure that the discharge capacity change in the cell is not higher than 3% of the rated capacity specified in the standard GB38031 [24]. As shown in Figure 1a, to investigate the temperature response of batteries under thermal abuse, we conducted ARC experiments. The 300 W heating source was used to heat the battery on one side to trigger TR, and the experimental setting is shown in Figure 1b. The battery was close to the heating plate of the same size and shape and was placed above the heat insulation plate. The ARC mainly tests the thermal characteristics of cells according to the \"heat-wait-search\" rule. In order to accurately monitor the battery's temperature change, multiple K-type thermocouples are arranged on the surface of the battery, as shown in Figure 1c. The accuracy of the K-type thermocouples used in this study is specified as \(\pm\)1.5 \({}^{\circ}\)C, which ensures reliable temperature measurements within the specified range. When the surface temperature of the battery reaches the preset target value, the resistance wire stops heating, and the experiment enters the \"wait-search\" stage. In this phase, the experiment mainly monitors whether the battery is able to maintain its temperature or whether the battery shows signs of temperature increase. If the temperature rise rate of the battery is detected at or above 0.02 \({}^{\circ}\)C min\({}^{-1}\), this usually indicates that the battery has started to generate its own heat; that is, there may be a slight failure inside the battery. In order to simulate the adiabatic environment during the self-generating phase, the ARC adjusts the heating power of the resistance wire to ensure that the air temperature in the calorimetric chamber is consistent with the surface temperature of the battery. This setting helps to ensure that the battery does not exchange heat with the outside world and that it more accurately simulates and analyzes the TR behavior that may occur in the battery under real use conditions. The entire process continues until the battery TR process naturally ends. The TR heat generation model can be built according to the TR side reaction mechanism of the battery, and its accuracy can be verified by the experimental results. The TR chemical reaction includes 7 main processes: SEI film decomposition, negative electrode and electrolyte reaction, separator decomposition, electrolyte decomposition, positive electrode decomposition, large-scale internal short circuit, and adhesive decomposition. Under normal working conditions, the separator can block electrons. When the TR progress to the separator collapses, electrons and lithium ions are present at the same time in the positive and negative electrode shuttle. A large-scale internal short circuit is formed, which releases a lot of heat, leading to the occurrence of other reactions. The thermal model parame