MoS₂/Graphene Hybrid Nanoflowers with Enhanced Electrochemical Performances as Anode for Lithium-Ion Batteries

Abstract

In this work, we studied the synthesis and electrochemical performance of MoS 2 and reduced graphene oxide (rGO) hybrid nanoflowers for use as anode material in lithium ion batteries (LIBs). The morphology and microstructure of the samples were characterized by field emission scanning electron microscopy (FESEM), Transmission electron microscopy (TEM), Xray diffraction (XRD) and X-ray photoelectron spectrometry (XPS). Herein, the composite nanoflowers delivered a significant enhanced reversible specific capacity and charge/discharge cycle stabilities as anode in comparison with pristine MoS 2 . Electrochemical impedance spectroscopy (EIS) measurements indicated that the incorporation of rGO significantly reduced the contact resistance and the improved electrochemical performances could be attributed to the synergy effect between the functions of MoS 2 and rGO. A high reversible capacity of 1150 mAh/g at a current of 0.1 A/g could retain without fading after 60 cycles. The rate performance of the composite was also improved, and the specific capacity remained a relative high value of mAh/g even at a current of 1000 mA/g. In order to further systematically study the mechanism of the improved LIBs performances for composite, we constructed the corresponding models based on experiment data and conducted first-principles calculation. Nudged elastic band (NEB) method was employed to study the diffusion of Li in different structures. The calculated results proved that the diffusion barrier for Li in MoS 2 /graphene was significantly lower than that of in pristine MoS 2 and presented a theoretical explanation for a better diffusivity property. The high specific capacity and excellent cycling stability of these hybrid nanoflowers are competent as a promising anode material for high-performance LIBs.

Interlayer Nanoarchitectonics of Two‐Dimensional Transition‐Metal Dichalcogenides Nanosheets for Energy Storage and Conversion Applications

“…Such sandwiched MoX 2 :C superstructures have been a hotspot for applications as high-performance electrodes in LIBs, [70,76,81,102,[106][107][108]119] SIBs [111,114] and MIBs. [120,121] The approaches for synthesizing sandwiched MX 2 :C superstructure typically include (i) exfoliation/restacking method by incorporating graphenes or organic molecules that can be easily carbonized upon annealing, [70,121] (ii) hydrothermal/ solvothermal methods with addition of pre-synthesized graphenes and carbon quantum dots that can be intercalated into MX 2 , [102,106,119] and (iii) hydrothermal/solvothermal methods that contain organic molecules, such as glucose, PVP, octylamine, oleic acid, dopamine, CTAB, that can be intercalated and carbonized. [76,108,114] For ) and long cycle life (over 500 cycles).…”

1T′‐ReS2 Confined in 2D‐Honeycombed Carbon Nanosheets as New Anode Materials for High‐Performance Sodium‐Ion Batteries

“…As shown in Figure 4a,b, the adsorption energy (E ad ) of a single Na atom of the ReS 2 system (−0.86 eV) is greater than that for the ReS 2 /graphene system (−1.35 eV). [54,[61][62][63] It is concluded that the unique structure of the new 2D-honeycombed nanosheet significantly boosts the electrochemical performance of 1T′-ReS 2 for SIBs. Moreover, this result is confirmed by the charge density differences.…”

“…Energy Mater. [54,59,60] Therefore, in a number of studies relating to 2D carbon/TMD or rGO/TMD materials, [54,[61][62][63] the 2D rGO or carbon was simplified into a graphene model in the DFT approach. [54][55][56][57][58] The influence of carbon incorporation on ReS 2 was investigated by DFT, to determine electrical conductivity and Na + adsorption/diffusion.…”

“…2019, 9,1901146 It is therefore concluded that the 2D-honeycombed carbon with extensive meso-/macro-pores protects the ReS 2 from sulfide dissolution and maintains nanosheet morphology and electrochemical activity of materials during long-term cycles. [54,[61][62][63] In this work, we therefore chose ReS 2 and simplified graphene-ReS 2 models to study the influence of graphene incorporation on physical properties of electrical conductivity and Na + adsorption/diffusion of ReS 2 . Because the obtained carbon materials of rGO inter-layer and N-doped carbon coating-layer are "special," and not well-defined, it is difficult to construct an accurate model of rGO or N-doped carbon.…”

Molybdenum disulfide quantum dots: synthesis and applications

“…Therefore, the stability of MoS 2 remains constant during continuous charge/discharge phenomena. [90] There are numerous reports for MoS 2 and its composites utilized as anode material for Li-ion batteries. [91][92][93] Consequently, MoS 2 QDs was selected as a surface sensitizer to boost the electrochemical properties of Li 4 Ti 5 O 12 .…”