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

Graphical An upscaling opportunity : Polyethyleneimine (PEI) modified GO sheets (PEI−GO) absorb the ammonium thiomolybdate on the surface via electrostatic attraction, accompanying with the layer-by-layer assembling in the solution. The subsequent annealing process creates a sheet-on-sheet structure with unilaminar MoS 2 nanosheets lie on the GR sheets. Two-dimensional (2D) heterostructured materials, combining the desired advantages of individual 2D materials and eliminating the associated shortcomings, have inspired great interest in electrochemical energy storage applications. But searching a highly efficient and practical method for preparing 2D heterostructures as electrode materials is still challenging. Herein, a 2D MoS 2 /graphene (GR) heterostructure is synthesized through a facile and accessible self-assembly method, which includes adsorbing ammonium thiomolybdate onto graphene oxide (GO) surface via electrostatic attraction and subsequently annealing the precursor to heterostructure. A high loading amount (86.2 %) of unilaminar MoS 2 nanosheets lie on the GR sheets forming a face-to-face structure, and the MoS 2 nanosheets exhibit a largely expanded interlayer spacing (1.0–1.2 nm) resulting from the alternately stacked structure during self-assembly process. As a Li-ion intercalation host, this unique MoS 2 /GR heterostructure exhibits pseudocapacitance-dominated characteristics with superior kinetic performances and extremely high structural stability. These characteristics afford MoS 2 /GR heterostructure remarkable rate capability (155.6 mAh g −1 at 4 A g −1 ; 119.3 mAh g −1 at 16 A g −1 ) and a durable reversible capacity (over 5000 cycles). This method is suitable for mass production of MoS 2 /GR heterostructure and paves a way for utilizing 2D heterostructured materials in Li-ion or other metal ion batteries.