Few-layer MoS2 nanosheets anchored by CNT network for superior lithium storage

A 3D Multilevel Heterostructure Containing 2D Vertically Aligned MoS2 Nanosheets and 1D Sandwich C-MoS2-C Nanotubes to Enhance the Storage of Li+ Ions

To overcome the disadvantages of the MoS₂ anode for LIBs in terms of low intrinsic conductivity, poor mechanical stability, and adverse reaction with electrolytes, a 3D multilevel heterostructure (VANS-MoS₂-CNTs) has been successfully prepared by a simple hydrothermal method followed by thermal treatment. VANS-MoS₂-CNTs are made up of 2D vertically aligned MoS₂ nanosheets (VANS) and 1D sandwich C-MoS₂-C nanotubes (CNTs). The sandwich-like nanotube is the core part, which is made up of the MoS₂ nanotube covered by carbon layers on both side surfaces. Due to the special heterostructure, VANS-MoS₂-CNTs have good conductivity, high structured stability, and excellent Li⁺/electron transport, resulting in high discharge capacity (1587 mAh/g at a current density of 0.1 A/g), excellent rate capacity (1330 and 730 mAh/g at current densities of 0.1 and 2 A/g, respectively), and good cyclic stability (1270 mAh/g at 0.1 A/g after 100 cycles).

Hierarchical Porous MoS2/C Nanospheres Self-Assembled by Nanosheets with High Electrochemical Energy Storage Performance

To overcome the deficiency of the volume expansion of MoS₂ as the anode material for lithium-ion batteries (LIBs), an effective strategy was developed to design hierarchical porous MoS₂/carbon nanospheres via a facile, easy-operated hydrothermal method followed by annealing. FESEM and TEM images clearly showed that nanospheres are composed of ultra-thin MoS₂/C nanosheets coated with carbon layer and possess an expanded interlayer spacing of 0.98 nm. As anodes for LIBs, MoS₂/carbon nanospheres deliver an initial discharge capacity of 1307.77 mAh g^-1 at a current density of 0.1 A g^-1. Moreover, a reversible capacity of 612 mAh g^-1 was obtained even at 2 A g^-1 and a capacity retention of 439 mAh g^-1 after 500 cycles at 1 A g^-1. The improved electrochemical performance is ascribed to the hierarchical porous structure as well as the intercalation of carbon into lattice spacing of MoS₂, which offers fast channels for ion/electron transport, relieves the influence of volume change and increases electrical conductivity of electrode. Meanwhile, the expanded interlayer spacing of MoS₂ in MoS₂/C can decrease the ion diffusion resistance and alleviate the volumetric expansion during discharge/charge cycles.