title: Melamine-assisted one-pot synthesis of hierarchical nitrogen-doped carbon@MoS₂ nanowalled core-shell microspheres and their enhanced Li-storage performances.
abstract: A facile and scalable one-pot approach has been developed to synthesize carbon@MoS2 core-shell microspheres by a hydrothermal method, which involves the fast formation of melamine-resorcinol-formaldehyde polymeric microspheres in situ, followed by direct growth of the MoS2 nanowalls on them. The results give unequivocal proof that melamine could be the key to forming the core-shell microspherical morphology, and the contents of MoS2 shells can be easily tuned by initial ratios of the precursors. After a simple heat treatment, the obtained carbon@MoS2 microspheres simultaneously integrate the nitrogen-doped carbon cores and the hierarchical shells which consist of few-layered MoS2 nanowalls with an expanded interlayer spacing. Their unique architectures are favourable for high electronic/ionic conductivity and accommodate volume strain during the electrochemical reaction of the MoS2 anodes in lithium-ion batteries. Thus, a very high reversibility capacity of 771 mA h g(-1) at 100 mA g(-1) after 100 cycles, and a rate capacity of 598 mA h g(-1) at 2000 mA g(-1) could be achieved for the carbon@MoS2 core-shell microspheres with the optimal composition. Furthermore, a thin carbon coating on the carbon@MoS2 microspheres could further increase the reversible capacity to 856 mA h g(-1) after 100 cycles at 100 mA g(-1). These encouraging results suggest that such a facile and efficient protocol can provide a new pathway to produce hierarchical core-shell microspheres which integrate the structural, morphological and compositional design rationales for advanced lithium-ion batteries.
authors.affiliation: Lab of Low-Dimensional Materials Chemistry, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China. jlshi@mail.sic.ac.cn.
authors.forename: Fugen
authors.initials: F
authors.lastname: Sun
authors.forename: Yanju
authors.initials: Y
authors.lastname: Wei
authors.forename: Jianzhuang
authors.initials: J
authors.lastname: Chen
authors.forename: Donghui
authors.initials: D
authors.lastname: Long
authors.forename: Licheng
authors.initials: L
authors.lastname: Ling
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Li
authors.forename: Jianlin
authors.initials: J
authors.lastname: Shi