Engineering Vertical Aligned MoS2 on Graphene Sheet Towards Thin Film Lithium Ion Battery

Ultrathin MoS2 nanosheets vertically aligned on the single layer graphene sheet (MoS2-NS/G) were synthesized by a simple CVD method. It is found that the single layer graphene plays important roles not only in the synthesis process but also in the electrochemical performance. The favorable vertical design can offer remarkable advantages such as fast electron transport/collect ion and ion diffusion, reduced charge-transfer resistance, and facile accommodation of the strains caused by lithium intercalation and deintercalation. The MoS2-NS/G was calculated to show the highest capacity of 620 mAh g−1 in these electrodes at a large current density of 4 A g−1 for 1000 cycles. It also delivers a good long-life cycling performance at high capacity of 1040 mAh g−1. Additionally, the excellent rate performance of MoS2-NS/G may be due to the heterostructure of graphene and MoS2. It is also found that the charge storage of MoS2 contains capacitive process. Because electrons can directly transport from the current collector to the electrolyte along MoS2 basal planes, the need for carbon black and binder is eliminated. It is believed that the MoS2-NS/G also has immense potential for applications in supercapacitor.