Directionally assembled MoS2 with significantly expanded interlayer spacing: a superior anode material for high-rate lithium-ion batteries

Abstract

Despite the great promise of molybdenum disulfide (MoS₂) as a storage anode for rechargeable lithium-ion batteries, the corresponding rate capacity is limited by the low electrical conductivity and kinetic barriers linked to ion diffusion, which prevents MoS₂ from being used in current electrical energy storage devices. A feasible strategy is reported to tackle these challenges by directionally growing MoS₂ nanosheets with an expanded interlayer spacing (i.e., 9.4 Å versus 6.15 Å for pristine 2H-MoS₂) on multiwalled carbon nanotubes (MWCNTs), which is performed through the microwave-assisted solvothermal reduction of ammonium tetrathiomolybdate [(NH₄)₂MoS₄] in dimethylformamide in the presence of MWCNTs. The intimate interfaces between the MoS₂ edges and the MWCNTs as well as the expanded interlayer gaps in MoS₂ offer efficient and rapid pathways for ion and electron transport, which is favorable for improving the performance of batteries and enables the highest rate capability to be achieved. Batteries containing the as-synthesized MoS₂/MWCNT anodes can constantly deliver a reversible capacity of 390 mA h g⁻¹ at a current rate of up to 57.312 A g⁻¹ (36C), describing the first class of MoS₂-based anodes promising for high-rate use.