## 3 Simulation Results and Optimizing Parameter Determination  
The results of thermal field simulation for the C0 are shown in Figure 5. According to the discharge temperature-time variation curve in Figure 5a, the temperature at the junction of the positive connecting piece and the tab piece stacking contact area exhibits an exponential increase, reaching the melting point of aluminum (660 \({}^{\circ}\)C) within 0.54 s. From the temperature distribution cloud diagram of the conductor structures in Figure 5b, it is evident that under the simulated condition of continuous 10 kA discharge for 0.54 s, the temperature distribution within the conductor structures is highly uneven. The key temperature observations indicate that the maximum instantaneous temperatures of the positive connecting piece and the positive tab both reach 660 \({}^{\circ}\)C, while the negative connecting piece and the negative tab reach 462.53 \({}^{\circ}\)C. Notably, the first place to heat up is the stacked weld between the connector and the lug. The temperature at the cathode was 349.77 \({}^{\circ}\)C and 605.94 \({}^{\circ}\)C at 0.2 s and 0.4 s, respectively. The highest temperature (660 \({}^{\circ}\)C) is concentrated at the junction of the positive connecting piece and the tab stack contact area. Due to the geometrical discontinuity at the junction, a region of temperature concentration is formed, leading to local overheating. This localized thermal stress results in a weak point, susceptible to thermal runaway, significantly impacting the overall safety and stability of the battery system under extreme high-current conditions. Figure 4: Schematic diagram of battery discharging test for different conductor structures. The simulation results in Figure 6 show that the temperature at the junction of the contact/non-contact area of the positive connecting piece, tab, and welded reinforcement structural part increases exponentially, reaching the melting point of aluminum (660 \({}^{\circ}\)C) in 0.68 s. As observed in the temperature distribution contour diagram (as shown in Figure 6b), under a continuous 10 kA discharge for 0.68 s, the temperature distribution across the conductor structures remains uneven. The first place to heat up is the stacked weld between the connector and the lug. The temperature at the cathode was 247.01 \({}^{\circ}\)C and 442.7 \({}^{\circ}\)C at 0.2 s and 0.4 s, respectively. The instantaneous temperature of the positive connecting piece and positive tab both reach 660 \({}^{\circ}\)C, while the negative connecting piece and negative tab reach 666.58 \({}^{\circ}\)C and 666.72 \({}^{\circ}\)C, respectively. The maximum temperature (660 \({}^{\circ}\)C) is concentrated at the junction of the contact/non-contact area of the positive connecting piece, tab, and welded reinforcement structural part. The simulation results in Figure 7a show that the temperature at the junction of the contact/non-contact area of the positive connecting piece, tab, and welded reinforcement structural part increases exponentially, reaching the melting point of aluminum (660 \({}^{\circ}\)C) in 1.73 s. As observed in the temperature distribution contour diagram (as shown in Figure 7b), under a continuous 10 kA discharge for 1.73 s, the temperature distribution across the conductor structures remains uneven. The first place to heat up is the stacked weld between  
Figure 5: Results of thermal field simulation for C0 group: (**a**) variation curve of temperature in different structure parts with discharging time; (**b**) temperature field of conductor structures. Figure 6: Results of thermal field simulation for T1 group: (**a**) variation curve of temperature in different structure parts with discharging time; (**b**) temperature field of conductor structures. the connector and the lugs. The temperatures at the cathode were 274.71 \({}^{\circ}\)C and 406.41 \({}^{\circ}\)C at 0.4 s and 0.8 s, respectively.