Synergy of Cobalt Single Atoms and Mesoporous Single-Layered Molybdenum Sulfide/Carbon Composites for Enhanced Sodium Ion Storage

Abstract Molybdenum disulfide (MoS2)-based nanomaterials are considered promising anodes for sodium-ion batteries (SIBs), but their practical application remains constrained by sluggish electrochemical kinetics and structural degradation induced by irreversible compositional conversion. Herein, we propose a synergistic interfacial engineering strategy that integrates atomically dispersed cobalt single-atom catalytic sites within a nitrogen-doped, mesoporous single-layered molybdenum sulfide/carbon hybrid architecture (SA Co-MoS2/C) via a versatile dual-template synthesis. Advanced structural characterizations and X-ray absorption spectroscopy reveal that the incorporation of Co single-atom sites triggers a partial semiconducting 2H-to-metallic 1T phase transition and drives substantial electron transfer from Co sites to the MoS2/C substrate. Consequently, the optimized SA Co-MoS2/C electrode delivers exceptional electrochemical performance, featuring a superior rate capability of 130 mAh g−1 at 6.0 A g−1 and robust cycling stability with a retained capacity of ∼300 mAh g−1 after 1000 cycles at 2.0 A g−1. These substantial performance enhancements are fundamentally attributed to the synergistic effects of single-atom catalytic sites and single-layered MoS2/C nanostructure, which collectively accelerate reaction kinetics and ensure highly reversible conversion chemistry. This work provides a compelling paradigm for precise interfacial regulation in transition metal dichalcogenides, offering valuable insights for designing high-performance energy storage materials.