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

Reducing SF 6 (as gas cathode) in Li batteries is a promising concept for the double benefit of mildly converting greenhouse SF 6 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  SF 6 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)  N 4 sites to catalyze the SF 6 electrochemical reduction. By using highly porous holey nitrogen-doped carbon nanocages as carbon matrix, the Li  SF 6 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 SF 6 in lithium batteries.