Lithium Intercalation in Graphene/MoS₂ Composites: First-Principles Insights

Abstract

As a storage material for Li-ion batteries, graphene/molybdenum disulfide (Gr/MoS 2 ) composites have been intensively studied in experiments. But the relevant theoretical works from first-principles are lacking. In the current work, van-der-Waals-corrected density functional theory calculations are performed to investigate the interaction of Li in Gr/MoS 2 composites. Three interesting features are revealed for the intercalated Gr/Li(n)/MoS 2 composites (n = 1 to 9). One is the reason for large Li storage capacity of Gr/MoS 2 : due to the binding energies per Li atom increase with the increasing number of intercalated Li atoms. Secondly, the band gap opening of Gr is found, and the band gap is enlarged with the increasing number of intercalated Li atoms, up to 160 meV with nine Li; hence these results suggest an efficient way to tune the band gap of graphene. Thirdly, the Dirac cone of Gr always preserve for different number of ionic bonded Li atoms. TOC Graphic:

Chemical Mass Production of MoS2/Graphene van der Waals Heterostructure as a High‐Performance Li‐ion Intercalation Host

“…It is obvious that MoS 2 /GR heterostructure exhibits markedly better electrochemical kinetic compared with MoS 2 /GR hybrid, well agreeing to the results of the CV measurement. The superior electrochemical kinetic of MoS 2 /GR heterostructure should be ascribed to the important role of MoS 2 /GR heterointerfaces in increasing the electronic conductivity of MoS 2 , enlarging the adsorption energy of Li‐ion on the surface of MoS 2 layer, and maintaining the high diffusion mobility of Li‐ion . Furthermore, the ultrasmall MoS 2 nanosheets can effectively shorten the Li‐ion transport path with more active sites for Li‐ion adsorption and reaction .…”

“…Furthermore, several theoretical studies have revealed that the MoS 2 /GR atomic interface possesses an enhanced Li adsorption energy compared with MoS 2 sheets . The Li‐ions can diffuse faster between GR and MoS 2 layers with a lower diffusion barrier than that in MoS 2 interlayers . Moreover, MoS 2 /GR heterointerfaces can achieve a maximum intercalation at the ratio of 1 Li per Mo atom, this means the interlayer‐expanded MoS 2 resulting from the alternately stacked structure can possess an enhanced charge storage capability.…”

“…[26,27] The Li-ions can diffuse faster between GR and MoS 2 layers with a lower diffusion barrier than that in MoS 2 interlayers. [28][29][30] Moreover, MoS 2 /GR heterointerfaces can achieve a maximum intercalation at the ratio of 1 Li per Mo atom, [31] this means the interlayer-expanded MoS 2 resulting from the alternately stacked structure can possess an enhanced charge storage capability. With these advantages, MoS 2 /GR heterostructure should be very suitable to serve as an intercalation host material for Li-ions.…”

Pressure‐Assisted Interface Engineering in MoS2/Holey Graphene Hybrids for Improved Performance in Li‐ion Batteries

“…The first discharge curve also detected a plateau at 1.6 V, and this value is higher than the potential characteristic for the formation of Li x MoS 2 intercalates. Theoretical studies have shown that heterostructures consisted of MoS 2 and graphene (G) accommodate lithium between the layers . Such MoS 2 / x Li/G intercalates are more stable by 0.41 eV as compared to the Li x MoS 2 intercalates .…”

Simple and Controllable Synthesis of Three‐Dimensional Spheroidal Structure of MoS2/rGO under Lower Temperature for Enhanced Properties in Lithium Battery

“…Graphene can be used as a carrier to prevent agglomeration of the MoS 2 sheet, so that the electrolyte is sufficiently in contact with the active material, improving the utilization ratio of the active material. Graphene also has good conductivity and high specific surface area, which can effectively improve the charge and discharge rate of MoS 2 …”