Multifunctional cationic molecular brushes-assisted fabrication of two-dimensional MoS2/carbon composites for ultrafast and long-term sodium storage

Molybdenum disulfide (MoS2) is considered as a promising anode for sodium-ion batteries (SIBs) because of its large interlayer space and high theoretical capacity. However, its practical application is seriously hampered by low electrical conductivity, sluggish reaction kinetics, and huge volumetric change. Herein, a class of two-dimensional (2D) sandwich-like carbon hybrids with MoS2-carbon nanoplates anchored on reduced graphene oxide (rGO) (rGO@MoS2–C) is successfully fabricated by homogeneously immobilizing abundant Mo anion on the surface of multifunctional cationic molecular brushes. The homogeneously dispersed MoS2 provides a large sodium-storage capacity, while the 2D rGO skeleton enables high electrical conductivity and rich surfaces/interfaces, and the amorphous carbon layers act as robust framework to address the volumetric expansion of MoS2. Benefiting from the elaborately integration of these merits, the rGO@MoS2–C with a MoS2 mass loading up to 87 wt% can realize excellent rate capability (348 mA h g−1 at 5 A g−1) as well as long-life cycling performance (305 mA h g−1 at 1 A g−1 after 2100 cycles), demonstrating great potential for practical application of SIBs.