Mesoporous N‐rich Carbon with Single‐Ni Atoms as a Multifunctional Sulfur Host for Li‐S Batteries

Physicochemical confinement and catalytic conversion of lithium polysulfides (LiPSs) are crucial to suppress the shuttle effect and enhance the redox kinetics of lithium‐sulfur (Li‐S) batteries. In this study, a NH4Cl‐assisted pyrolysis strategy is developed to fabricate highly mesoporous N‐rich carbon (designed as NC(p)) featuring thin outer shells and porous inner networks, on which single‐Ni atoms are anchored to form an excellent sulfur host (designed as Ni‐NC(p)) for Li‐S batteries. During pyrolysis, the pyrolytic HCl from confined NH4Cl within ZIF‐8 will in situ etch ZIF‐8 to produce rich mesoporous in the carbonized product NC(p). The mesoporous Ni‐NC(p) enables favorable electron/ion transfer, high sulfur loading, and effective confinement of LiPSs, while the catalytic effect of single‐Ni species enhances the redox kinetics of LiPSs. As a result, the sulfur cathode based on the Ni‐NC(p) host delivers obviously improved Li‐S battery performance with high specific capacity, good rate capability, and cycling stability. Highly mesoporous N‐rich carbon with single‐Ni sites (Ni‐NC(p)) is synthesized by a novel and facile strategy and employed as a multifunctional sulfur host for Li‐S batteries. The unique architecture, N dopant, and single‐Ni atoms enable the effective confinement and fast redox kinetics of lithium polysulfides towards efficient Li‐S batteries.