Synergistic sodium ion-pillaring and three-dimensional carbon armoring of molybdenum disulfide for aqueous zinc-ion batteries with ultrahigh capacity and cyclability.

The practical application of layered molybdenum disulfide (MoS2) cathodes in aqueous zinc-ion batteries (AZIBs) is limited by narrow interlayer spacing, poor conductivity of the semiconducting two-layer hexagonal phase, and structural degradation during cycling. Developing an integrated strategy that can simultaneously improve ion transport, electron conduction, and structural stability remains a key challenge. Herein, we report a combined sodium ion (Na+) preintercalation and three-dimensional (3D) honeycomb carbon (HC) confinement system to regulate the intrinsic properties and external architecture of MoS2. The preintercalated Na+ acts as structural pillars, expanding the interlayer distance from 0.62 nm to 0.89 nm and stabilizing the metallic one trigonal phase with improved hydrophilicity and conductivity. Concurrently, the bicontinuous HC framework serves as a conductive and robust matrix that alleviates volume variation, suppresses nanosheet restacking, and facilitates charge transport. The resulting Na-MoS2@HC cathode exhibits strong rate capability and stable cycling performance, maintaining high reversible capacities at current densities of 2 and 5 A g-1, and 99.3% capacity retention after 2000 cycles at 5 A g-1. Kinetic analysis indicates a dominant pseudocapacitive contribution, while density functional theory calculations show a substantially reduced Zn2+ diffusion barrier. Ex situ characterizations further confirm a reversible Zn2+ insertion-extraction process. The assembled quasi-solid-state battery shows good flexibility and stable electrochemical performance, indicating the practical potential of this material design. Overall, our study shows that synergistic coengineering of interlayer spacing and phase structure provides a practical route for developing high-performance layered cathodes for AZIBs.