Ultrathin MoS2 anchored on 3D carbon skeleton containing SnS quantum dots as a high-performance anode for advanced lithium ion batteries

Abstract

Transition metal sulfides have high abundance and large theoretical capacities are considered to be an effective candidate for advanced electrodes of lithium ion batteries (LIBs). Here, a large-scale and controllable method was used in synthesizing ultrathin MoS2 nanosheets anchored on 3D hierarchical nanohybrids with SnS quantum dots, which are decorated on a carbon nanosheet network (MoS2@SnS-QDs/CNN). The 3D cross-linked carbon nanosheet not only could prevent SnS from being directly exposed to the electrolyte but also retained the structural stability of the electrode. Moreover, the MoS2 nanosheets exposed active sites to carry lithium ions. A heterojunction was formed at the interface owing to the close contact between molybdenum disulfide and SnS and greatly increased charge carrying and lithium storage capacities. Benefiting from these structural advantages, the MoS2@SnS-QDs/CNN electrodes showed outstanding electrochemical and long-term cycling performance owing to their unique structures and amazing synergies. As a half-cell anode material, MoS2@SnS-QDs/CNN-2 provided a reversible capacity of 713 mAh g−1 after 1000 cycles at a current density of 2 A g−1. When assembled into a full battery, it still provided 491 mAh g−1 at a current density of 1 A g−1 after 100 cycles. At the same time, a small LED bulb was lit for a while. This advanced material has great potential in other applications, such as supercapacitors, catalysis, and sensors.