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

Abstract

Abstract 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.

Keywords

• Lithium-ion batteries
• Anode materials
• MoS2/C
• Porous structure
• Electrochemical performance