Monolayer MoS2 Enabled by Intercalation-Confinement Synergy Toward Ultrafast and Stable Sodium Storage.

Molybdenum disulfide (MoS2) has been extensively studied as the anode material for sodium-ion batteries (SIBs). However, conventional synthesis methods typically produce stacked-layer MoS2 nanosheets with inherent limitations, such as poor electrical conductivity, high ion diffusion barriers, and substantial volume variations during cycling. Herein, we propose a novel dual-driving strategy based on an intercalation-confinement synergy to prepare monolayer MoS2 nanosheets successfully encased in nitrogen-doped carbon (NC) shells (MoS2/NC@NC). The obtained unique hollow architecture enables the full exposure of monolayer MoS2 to the electrolyte and promotes multidirectional sodium-ion (Na+) transport, leading to enhanced ion diffusion kinetics. Theoretical calculations combined with finite element simulations corroborate the superior properties of the hollow nanostructures, revealing the enhanced conductivity, favorable Na+ diffusion kinetics, and exceptional mechanical robustness. As a result, the as-fabricated MoS2/NC@NC anode exhibits an ultrahigh rate capability (311.3 mAh g-1 at 20 A g-1) and exceptional long-term cyclability, with an ultralow capacity decay of 0.0027% per cycle over 10,000 cycles. To demonstrate practical applicability, the assembled full cell successfully powers the "QUST" logo composed of 44 commercial LEDs. This work paves the way for preparing monolayer MoS2 with superb sodium storage performance.