## 3 Results and Discussion
NEDC simulation results for the power consumption of the LSB and LIB in Figure 4c,d, respectively, indicate that the LSB had an obvious larger power loss during vehicle driving, and the peak loss of the LSB during the NEDC cycle was 9.2 kW at 1120 s, while that of the LIB was 1.2 kW at 1121 s. The simulation energy consumption by the end of the NEDC  
Figure 4: (**a**) LSB voltage under the NEDC; (**b**) LIB voltage under the NEDC; (**c**) LSB power consumption; (**d**) LIB power consumption; (**e**) LSB energy consumption; (**f**) LIB energy consumption. driving cycle at 1200 s is shown in Figure 4e,f for the LSB and LIB, respectively, revealing that the driving energy consumption and battery energy consumption for the LSB were 1.526 kWh and 1.646 kWh, respectively, in other words, a battery energy loss of 0.12 kWh, while for the LIB, they were 1.542 kWh and 1.558 kWh, respectively, a battery energy loss of 0.016 kWh. This simulation clearly indicated that the LSB had a very notable battery energy loss, which was much higher than that of the LIB. The WLTC was the second driving cycle for the simulation analysis. The WLTC adds real road emissions requirements and significantly strengthens evaporative emissions control, which is closer to the realistic vehicle driving condition, and thus is a very important driving condition to evaluate the power-train system and is referred to by many vehicle test standards [33; 34; 35]. The WLTC speed curve is shown in Supplementary Figure S8b, and the simulation voltage curves under the WLTC for the LSB and LIB in Figure 5 reveal that the LSB underwent an extremely more severe output voltage vibration (288.2-440.9 V) than the LIB (324.5-357.1 V), and was also worse than that under the NEDC, as the WLTC has more frequent driving and braking demand change [36]. The results showed that the LSB's unstable voltage caused by a large internal resistance becomes worse in more aggressive driving conditions. Figure 5c,d shows the WLTC simulation of the power consumption for the LSB and LIB; the gap between driving power and battery power at certain time points indicates the battery power loss. Figure 5c,d indicates that the LSB had an obvious power loss during vehicle driving; the peak power loss during the WLTC was 19.4 kW at 1648 s, while the peak power loss of the LIB battery was 3.8 kW at 1652 s. The energy consumption during the WLTC is shown in Figure 5e,f; by the end of the WLTC, the driving energy consumption was 9.521 kWh, the battery energy consumption for the LSB was 11.98 kWh, with a battery energy loss of 2.459 kWh, while the energy consumption for the LIB was 9.277 kWh, with a battery energy loss of 0.056 kWh. Under the aggressive acceleration/deceleration defined by the WLTC, the large LSB internal resistance created more significant power loss and  
Figure 5: (**a**) LSB voltage under the WLTC (**b**); LIB voltage under the WLTC; (**c**) LSB power consumption under the WLTC; (**d**) LIB power consumption under the WLTC; (**e**) LSB energy consumption under the WLTC; (**f**) LIB energy consumption under the WLTC. energy loss, significantly reducing the electric vehicle energy efficiency. Finally, the HWFT cycle was used for this simulation to observe the battery performance under a continuous high-speed driving condition. The HWFT cycle is a chassis dynamometer driving schedule developed by the US EPA for light-duty vehicles. The speed curve of the HWFT cycle is shown in Supplementary Figure S8c. The LSB and LIB were further simulated using the HWFT cycle with an aggressive acceleration operation, thereby consuming a large current to result in an extremely severe output voltage vibration for the LSB (310.1-441.3 V), a much larger value than that of the LIB (339.7-357.6 V) in Figure 6a,b. Figure 6c,d discloses that the LSB had an obvious power loss during highway driving, and the peak power loss during the HWFT was 28.1 kW at 10.3 s, while the power loss for the LIB battery was only 6.2 kW at 10.1 s during the fast acceleration of the vehicle.