Co9S8@MoS2 core-shell nanostructure anchored on reduced graphene oxide with improved electrochemical performance for lithium-ion batteries

Abstract

Co9S8@MoS2 core-shell nanoparticles anchored on both sides of reduced graphene oxide (Co9S8@MoS2/rGO) were synthesized via hydrothermal reaction. The core-shell composites were used as an anode material and demonstrated enhanced electrochemical performance with high capacity, capacity retention, cycling stability, and rate capability during cycling tests. The nanocomposites deliver a reversible capacity of 2014.5 mAh g−1 at a high rate of 0.3 A g−1 with a capacity retention efficiency of 82.8% after 200 cycles. The reduced graphene oxide-based three-dimensional framework of the core-shell structure can reduce the internal resistance of the whole electrode, facilitate more Li+ ion insertion and extraction from the crystal structure, and relieve the strain caused by volume change during the lithiation/delithiation process. The electrochemical behaviors could make the composites a great potential anode material for lithium-ion batteries.