Electrochemically intercalated intermediate induced exfoliation of few-layer MoS2from molybdenite for long-life sodium storage

Two-dimensional (2D) molybdenum disulfide (MoS2) holds significant promise as an energy storage material, whereas the exfoliation of MoS(2)into few-layer from natural molybdenites remains a challenge. An efficient electrochemical strategy was proposed for the preparation of few-layer MoS(2)through cationic intercalation. Few-layer MoS(2)without the impurity phases was obtained with high yield through Raman mapping analysis, and the intermediate (TBA(+))(x)MoS(2)(x-)was captured byin-situRaman. Note that the charge transport kinetics of the exfoliated few-layer MoS(2)was further enhanced by the introduction of graphene, which could efficiently enhance the Na(+)diffusion mobility, alleviate the volume change of MoS(2)and stabilize the reaction products. Commendably, the exfoliated MoS2/graphene hybrid shows a reversible specific capacity of 642.8 mA h g(-1)at 0.1 A g(-1), superior rate performance (447.8 and 361.9 mA h g(-1)at 1 and 5 A g(-1), respectively) and remarkable long-cycle stability with 328.7 mA h g(-1)at 1 A g(-1)after 1000 cycles for sodium-ion batteries (SIBs). Therefore, this efficient electrochemical exfoliation method can be driven to prepare other few-layer 2D materials for SIBs.

Automated summary

An efficient electrochemical strategy was proposed for the preparation of few-layer MoS(2) without impurity phases through cationic intercalation, with the additional enhancement of charge transport kinetics by introducing graphene. The exfoliated MoS2/graphene hybrid exhibited superior performance in terms of reversible specific capacity, rate capability, and long-cycle stability for sodium-ion batteries.