Poly(diallyldimethylammonium chloride)-assisted synthesis of MoS2/graphene composites with enhanced electrochemical performances for reversible lithium storage

The MoS 2 /graphene composites were synthesized by a hydrothermal route in the presence of graphene oxide sheets with assistance from poly(diallyldimethylammonium chloride) (PDDA). The results of characterizations show that the MoS 2 /graphene composites exhibit a graphene-like morphology with interconnected network, in which single- or few-layer MoS 2 sheets are homogenously dispersed and well anchored on the graphene surface. The robust heterostructure and morphology of MoS 2 /graphene composites can not only provide more sites and channels for lithium ion accommodation and diffusion, but also facilitate electrolyte access. The heterostructure also maximizes the synergistic effects between MoS 2 and graphene. Therefore, MoS 2 /graphene composites exhibit significantly improved electrochemical performances for reversible lithium storage. In particular, the MoS 2 /graphene composite prepared with monomer concentration of PDDA being 0.02   mol   L −1 exhibits a reversible capacity of 1100   mA   h   g −1 with enhanced rate capability. The reversible capacity of 856   mA   h   g −1 after 900 cycles at 500   mA   g −1 can be remained, indicating its excellent cyclic stability.