Superior Performance of Activated Carbon Cathode Materials for Rechargeable Li-Cl 2 Batteries at Low Temperature

Rechargeable lithium-chlorine (Li-Cl 2 ) batteries have garnered significant interest due to their high energy density, yet challenges such as the cycling stability and low-temperature adaptability remain to be tackled. This study successfully applied high surface area activated carbon material (3200 m 2 g −1 ) to the cathode of a lithium-chlorine battery with AlCl 3, LiFSI, LiTFSI, LiCl, and SOCl 2 electrolytes, which demonstrate exceptional electrochemical performance. The results indicate that the Li-Cl 2 @AC battery can be cycled stably within a wide current density range of 0.5−5 A g −1 . Remarkably, the system exhibits an anomalous low-temperature enhancement effect: at −20 °C, a high capacity of 2000 mAh g −1 is demonstrated, and a stable charge/discharge for over 410 cycles is achieved, a performance significantly superior to that of room temperature. Mechanistic studies show that the low-temperature environment effectively reduces the generation of irreversible LiCl and enhances Cl 2 availability, thereby substantially extending the cycle life of the battery. This work not only demonstrates the potential of high surface area activated carbon materials in Li-Cl 2 batteries but also provides an innovative approach to addressing the low-temperature performance issue of high-energy-density lithium-chlorine batteries.