Enabling High‐Loading Aqueous Zinc–Sulfur Batteries Via a Ni Single‐Atom Catalytic Host with Hierarchical Sulfur Reservoirs

Aqueous zinc–sulfur batteries have drawn considerable interest owing to their high theoretical capacity, intrinsic safety, and cost‐effectiveness. Nevertheless, the sulfur cathode typically exhibits sluggish two‐electron solid‐state conversion reactions, resulting in a lower discharge voltage and inefficient sulfur utilization. Herein, we design a nickel single‐atom‐anchored on N‐doped carbon hollow structure featuring an internal three‐dimensional network‐like skeleton as the sulfur host to address these issues. The nickel single‐atom‐anchored on N‐doped carbon hollow structure synergistically combines atomic Ni‐N ₄ catalytic sites as well as a hollow structure possessing a high specific surface area and hierarchical nanopores. Consequently, the resulting S@Ni‐SAs/NCHS achieves a high sulfur loading of ~74 wt% and a specific capacity of 1664.6 mAh g ⁻¹ at 0.1 A g ⁻¹ with a low polarization of 0.35 V. Besides, it maintains a capacity of 1154.4 mAh g ⁻¹ at 5 A g ⁻¹ and shows a retained capacity of 1038.6 mAh g ⁻¹ after 1000 cycles at 2 A g ⁻¹ , which corresponds to a decay rate of 0.03% per cycle. Density functional theory calculations reveal that the Ni‐N ₄ site serves as an efficient electron donor, facilitating charge transfer and reducing the energy barrier of the rate‐determining step from 1.845 eV to 1.458 eV. Furthermore, a pouch cell with a high areal sulfur loading demonstrates specific capacities of 1200–1400 mAh g ⁻¹ under various bending states with discharge plateaus about 0.8 V, retaining 83.4% capacity after 200 cycles. This work underscores the critical role of integrating Ni atomic catalysis with well‐developed porosity within the carbon hollow structure for developing high‐performance aqueous zinc–sulfur batteries.