Hydrogen-Bonded Organic Framework as Superior Separator with High Lithium Affinity CUN Bond for Low N/P Ratio Lithium Metal Batteries

Lithium dendrite and side reactionsare two major challengesforlithium metal anode. Here, the highly lithophilic triazine ring inthe hydrogen-bonded organic framework is recommended to acceleratethe desolvation process of lithium ions. Among them, the formationof Li-N bonds between lithium ions and the triazine ring inCAM reduces the diffusion energy barrier of Li+ crossingthe SEI interface and the desolvation energy barrier of Li+ exiting from the solvent sheath so that the rapid and homogeneousdeposition of lithium-ion can be achieved. Meanwhile, the lithium-ionmigration coefficient can be as high as 0.70. CAM separator is usedto assemble lithium metal batteries with nickel-rich cathodes (NCM622). When N/P = 8 and 5, the capacityretention rates of Li-NCM 622 full cell are 78.2% and 80.5% after200 and 110 cycles, respectively, and the Coulomb efficiency can bemaintained at 99.5%, showing excellent cycle stability.