Closely Coupled Binary Metal Sulfide Nanosheets Shielded Molybdenum Sulfide Nanorod Hierarchical Structure via Eco-Benign Surface Exfoliation Strategy towards Efficient Lithium and Sodium-ion Batteries

초록

Improving interfacial interactions by constructing heterostructures is gaining interest due to its unique structural benefits for ion-reservoir applications. However, great challenges remain. Herein, we propose MoS2 nanorod-based heterostructures covered with a closely interconnected Sn and Mo sulfides/carbon matrix (SMSC@MS-HS) (engraved by a simple water based surface exfoliation strategy) as an efficient anode material for Li/Na–ion storage. Our hierarchical SMSC@MS-HS electrode achieved remarkable discharge capacities of 1,060 and 490 mAh g−1 (after 100 cycles at 100 mA g−1) for lithium and sodium-ion batteries, respectively, along with high initial coulombic efficiency and rate capability. This well-constructed architecture provided facile Li+/Na+ ion diffusion and enhanced the charge transfer at the heterointerfaces. Meanwhile, the strong coupling of MoS2 with SnS during water exfoliation in the presence of a carbon matrix created a stable and shielded nanostructure, which significantly enhanced electron/ion transport and mitigated the volume expansion during cycling. These benefits were attributed to a prominent capacitive contribution from kinetics study, improved Li+/Na+ diffusion from galvanostatic intermittent titration measurements, and good structural stability from ex-situ analyses.

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