Self-Assembly-Induced Alternately Stacked Single-Layer MoS2 and N-doped Graphene: A Novel van der Waals Heterostructure for Lithium-Ion Batteries
Ang, Jia Ming
Lee, Pooi See
Date of Issue2016
School of Materials Science and Engineering
In this article, a simple self-assembly strategy for fabricating van der Waals heterostructures from isolated two-dimensional atomic crystals is presented. Specifically, dopamine (DOPA), an excellent self-assembly agent and carbon precursor, was adsorbed on exfoliated MoS2 monolayers through electrostatic interaction, and the surface-modified monolayers self-assembled spontaneously into DOPA-intercalated MoS2. The subsequent in situ conversion of DOPA to highly conductive nitrogen-doped graphene (NDG) in the interlayer space of MoS2 led to the formation of a novel NDG/MoS2 nanocomposite with well-defined alternating structure. The NDG/MoS2 was then studied as an anode for lithium-ion batteries (LIBs). The results show that alternating arrangement of NDG and MoS2 triggers synergistic effect between the two components. The kinetics and cycle life of the anode are greatly improved due to the enhanced electron and Li+ transport as well as the effective immobilization of soluble polysulfide by NDG. A reversible capacity of more than 460 mAh/g could be delivered even at 5 A/g. Moreover, the abundant voids created at the MoS2–NDG interface also accommodate the volume change during cycling and provide additional active sites for Li+ storage. These endow the NDG/MoS2 heterostructure with low charge-transfer resistance, high sulfur reservation, and structural robustness, rendering it an advanced anode material for LIBs.
Molybdenum disulfide (MoS2)
ACS Applied Materials & Interfaces
© 2016 American Chemical Society (ACS). This is the author created version of a work that has been peer reviewed and accepted for publication by ACS Applied Materials & Interfaces, American Chemical Society (ACS). It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1021/acsami.5b11492].