Water-Trapping Single-Atom Co-N₄ /Graphene Triggering Direct 4e^- LiOH Chemistry for Rechargeable Aprotic Li-O₂...

Lithium-oxygen (Li-O₂ ) batteries have received extensive attention owing to ultrahigh theoretical energy density. Compared to typical discharge product Li₂ O₂ , LiOH has attracted much attention for its better chemical and electrochemical stability. Large-scale applications of Li-O₂ batteries with LiOH chemistry are hampered by the serious internal shuttling of the water additives with the desired 4e^- electrochemical reactions. Here, a metal organic framework-derived "water-trapping" single-atom-Co-N₄ /graphene catalyst (Co-SA-rGO) is provided that successfully mitigates the water shuttling and enables the direct 4e^- catalytic reaction of LiOH in the aprotic Li-O₂ battery. The Co-N₄ center is more active toward proton-coupled electron transfer, benefiting - direction 4e^- formation of LiOH. 3D interlinked networks also provide large surface area and mesoporous structures to trap ≈12 wt% H₂ O molecules and offer rapid tunnels for O₂ diffusion and Li⁺ transportation. With these unique features, the Co-SA-rGO based Li-O₂ battery delivers a high discharge platform of 2.83 V and a large discharge capacity of 12 760.8 mAh g^-1 . Also, the battery can withstand corrosion in the air and maintain a stable discharge platform for 220 cycles. This work points out the direction of enhanced electron/proton transfer for the single-atom catalyst design in Li-O₂ batteries.