MoS2/C/C nanofiber with double-layer carbon coating for high cycling stability and rate capability in lithium-ion batteries

Abstract

MoS2 has attracted a lot of interest in the field of lithium-ion storage as an anode material owing to its high capacity and two-dimensional (2D)-layer structure. However, its electrochemical properties, such as rate capability and cycling stability, are usually limited by its low conductivity, volume variation, and polysulfide dissolution during lithiation/delithiation cycling. Here, a designed two-layer carbon-coated MoS2/carbon nanofiber (MoS2/C/C fiber) hybrid electrode with a double-layer carbon coating was achieved by a facile hydrothermal and subsequent electrospinning method. The double carbon layer (inner amorphous carbon and outer carbon fiber) shells could efficiently increase the electron conductivity, prevent the aggregation of MoS2 flakes, and limit the volume change and polysulfide loss during long-term cycling. The as-prepared MoS2/C/C fiber electrode exhibited a high capacity of up to 1,275 mAh/g at a current density of 0.2 A/g, 85.0% first cycle Coulombic efficiency, and significantly increased rate capability and cycling stability. These results demonstrate the potential applications of MoS2/C/C fiber hybrid material for energy storage and may open up a new avenue for improving electrode energy storage performance by fabricating hybrid nanofiber electrode materials with double-layer carbon coatings.