Enhancing the Reduction Kinetics of LiSF₆ Batteries by Dispersed Cobalt Phthalocyanines on Porous Carbon

Reducing SF₆ (as gas cathode) in Li batteries is a promising concept for the double benefit of mildly converting greenhouse SF₆ and providing a high theoretical energy density of 3922 Wh kg^-1 . However, the reduction process is hampered by its sluggish kinetics. Here, cobalt phthalocyanine (CoPc) molecules immobilized on porous carbon matrix are, for the first time, introduced to the LiSF₆ chemistry to deliver an enhanced energy density. It is revealed that the high redox potential of Co(II)Pc/[Co(I)Pc]^- (≈2.85 V) facilitates the formation of Co(I)N₄ sites to catalyze the SF₆ electrochemical reduction. By using highly porous holey nitrogen-doped carbon nanocages as carbon matrix, the LiSF₆ cells deliver a high discharge voltage of 2.82 V at 50 mA g_C+CoPc ^-1 and an unprecedented areal capacity of 25 mAh cm^-2 at 0.1 mA cm^-2 , much superior to previous results. This work opens up new possibilities for high-efficiency conversion of SF₆ in lithium batteries.