Dopamine-Induced Formation of Ultrasmall Few-Layer MoS 2 Homogeneously Embedded in N-Doped Carbon Framework for Enhanced Lithium-Ion Storage.

Molybdenum disulfide with a layered structure and high theoretical capacity is attracting extensive attention for high-performance lithium-ion batteries. In this study, a simple and scalable method by freeze-drying of (NH4 )2 MoS4 and dopamine mixed solutions along with subsequent calcination is developed to realize the self-assembly of hierarchical MoS2 /carbon composite nanosheets via the effect of dopamine-induced morphology transformation, in which ultrasmall few-layer MoS2 nanosheets were homogeneously embedded into a N-doped carbon framework (denoted as MoS2 @N-CF). The embedded ultrasmall MoS2 nanosheets (∼5 nm in length) in the composites consist of less than five layers with an expanded interlayer spacing of the (002) plane. When tested as anode materials for rechargeable Li-ion batteries, the obtained MoS2 @N-CF nanosheets exhibit outstanding electrochemical performance in terms of high specific capacity (839.2 mAh g-1 at 1 A g-1 ), high initial Coulombic efficiency (85.2%), and superior rate performance (702.1 mAh g-1 at 4 A g-1 ). Such intriguing electrochemical performance was attributed to the synergistic effect of uniform dispersion of few-layer MoS2 into the carbon framework, expanded interlayer spacing, and enhanced electronic conductivity in the unique hierarchical architecture. This work provides a simple and effective strategy for the uniform integration of MoS2 with carbonaceous materials to significantly boost their electrochemical performance.