## 3 Results and Discussion
The driving and battery energy consumptions by the end of the HWFT cycle, shown in Figure 6e,f, were 2.098 kWh and 2.334 kWh, respectively, for the LSB, there was a battery energy loss of 0.236 kWh, while they were 2.136 kWh and 2.174 kWh, respectively, while for the LIB, there was a battery energy loss of 0.038 kWh, clearly symbolizing that the LSB had a very notable battery energy loss in the HWFT cycle, further confirming its notable internal resistance. Supplementary Figure S9 summarizes the voltage oscillation, peak power loss, and total energy loss comparison between the LSB and the LIB. Due to its large internal resistance, the output voltage of the LSB is affected sensitively by unstable output voltage and more power loss, worse than that of the LIB. To evaluate the LSB performance during fast charge, a charging simulation was set up to observe the potential charge capability for EV. A fast-charge simulation strategy was designed as in the following List:  
1. Charge start: start the charge when the battery SOC is 20%. 2. Charge current ramp: ramp the charge current 1 A per second, until the charge current reaches the configured constant-charge current value. Figure 6: (**a**) LSB voltage under the HWFT cycle; (**b**) LIB voltage under the HWFT cycle; (**c**) LSB power consumption under the HWFT; (**d**) LIB power consumption under the HWFT; (**e**) LSB energy consumption under the HWFT; (**f**) LIB energy consumption under the HWFT. 3. Constant current charge: continuously charge with the configured current and decrease the charge current accordingly to avoid the battery output voltage reaching the voltage limit. 4. Charge stop: when battery SOC reaches 80%, stop charging. The fast-charge simulation results for the LSB are shown in Figure 7a-e. In a previous analysis, it can be noted from Equation (1) that the large internal resistance will raise the output voltage variance. Under certain fast-charge currents, the output voltage of the LSB increases more easily to reach the voltage limit because of its 10 times higher internal resistance compared to the LIB, and its charge current has to be limited to avoid the output voltage exceeding its limit threshold. To avoid exceeding the battery voltage limit (470 V), the charge current was set to 131 A for a constant current charge after the SOC reached 70%, at which point the OCV platform began to rise and the charge current had to be reduced for the voltage below the battery limit. Using this fast-charge strategy, it took 2681 s to charge the LSB from SOC 20% to SOC 80%. The fast-charge simulation results for the LIB battery are shown in Figure 7b-f. The charge current could be set to 255 A for a constant current charge, the LIB battery could be charged to 80% SOC with a 255 A constant voltage, and the battery voltage never exceeded the voltage limit (384 V) during the entire charging process. It took 508 s to charge the LSB from SOC 20% to SOC 80% by using the fast-charge simulation strategy. The charging simulation results are summarized in Table 3. From the simulation results, we found that the LSB's performance was good and that the LSB could adapt to the application of an electric vehicle under mild driving conditions; however, the high internal resistance of the LSB resulted in a sharp output voltage vibration, significant loss of peak power, and energy in the aggressive driving condition, which could affect the life and safety of the electrical systems, reduce the dynamic performance, and shorten the driving range of the EV. The charging time was five times longer than for the LIB, so the LSB could not meet the fast-charging requirement. Figure 7: (**a–e**) Fast-charge simulation results for the LSB; (**b–f**) fast-charge simulation results for the LIB.