Strong Coupling of MoS2 Nanosheets and Nitrogen‐Doped Graphene for High‐Performance Pseudocapacitance Lithium Storage

• DOI: 10.1002/smll.201704410
• Publication Date: 2018-05-24T06:51:12Z
• Authors: Zhendong Lei; Laiqiang Xu; Yalong Jiao; Aijun Du; Yong Zhang; Haijiao Zhang
• Keywords: Energy storage; lithium-ion batteries; 600; 2D Materials; 02 engineering and technology; MoS2 nanosheets; 540; 0210 nano-technology; nitrogen-doped graphene; 01 natural sciences; 7. Clean energy; 0104 chemical sciences

AbstractLayered material MoS2 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 MoS2 nanosheets and nitrogen‐doped graphene (MoS2/N‐G) composite is developed. In this composite, the interconnected MoS2 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 MoS2 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 MoS2 nanosheets and nitrogen‐doped graphene, which facilitates the charge transfer in the hybrid system. When used as the anode for LIBs, the resulting MoS2/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 MoS2/G electrode without employing the dopamine linker. Significantly, it is also identified that the thin MoS2 nanosheets display outstanding high‐rate capability due to surface‐dominated pseudocapacitance contribution.