Strong Coupling of MoS 2 Nanosheets and Nitrogen‐Doped Graphene for High‐Performance Pseudocapacitance Lithium Storage

Layered material MoS 2 is widely applied as a promising anode for lithium‐ion batteries (LIBs). Herein, a scalable and facile dopamine‐assisted hydrothermal technique for the preparation of strongly coupled MoS 2 nanosheets and nitrogen‐doped graphene (MoS 2 /N‐G) composite is developed. In this composite, the interconnected MoS 2 nanosheets are well wrapped onto the surface of graphene, forming a unique veil‐like architecture. Experimental results indicate that dopamine plays multiple roles in the synthesis: a binding agent to anchor and uniformly disperse MoS 2 nanosheets, a morphology promoter, and the precursor for in situ nitrogen doping during the self‐polymerization process. Density functional theory calculations further reveal that a strong interaction exists at the interface of MoS 2 nanosheets and nitrogen‐doped graphene, which facilitates the charge transfer in the hybrid system. When used as the anode for LIBs, the resulting MoS 2 /N‐G composite electrode exhibits much higher and more stable Li‐ion storage capacity (e.g., 1102 mAh g −1 at 100 mA g −1 ) than that of MoS 2 /G electrode without employing the dopamine linker. Significantly, it is also identified that the thin MoS 2 nanosheets display outstanding high‐rate capability due to surface‐dominated pseudocapacitance contribution.