Construction of MoS2@reduced graphene oxide/carbon nanotubes three-dimensional network structure and its application in lithium-sulfur batteries

Abstract

In order to enhance the electrochemical performance of lithium-sulfur batteries, reduced graphene oxide (rGO), and carbon nanotubes (CNTs) were used to construct a conductive and mechanical skeleton of the overall electrode composite. And molybdenum disulfide (MoS2) grew on the skeleton in situ. Thus, a composite MoS2@rGO/CNTs with a three-dimensional (3D) network structure was constructed. A series of corresponding structural characterizations and electrochemical performance tests were carried out. And the results showed that the 3D porous skeleton composed of rGO and CNTs could act as a 3D conductive network, which not only significantly improved the conductivity and structural stability of the cathode material for lithium-sulfur batteries but also provided a large number of active sites for the active substance S. MoS2 had a strong chemisorption effect on lithium polysulfides, which could effectively hinder their shuttle behavior. So, the MoS2@/CNTs/rGO/S cathode material showed good electrochemical performance. Its first discharge specific capacity was up to 1417.8 mAh/g at 0.1 C. After 200 cycles at 0.5 C, its capacity decay rate per cycle was only 0.09%. Its discharge capacity could still maintain at 803.2 mAh/g at 3 C, showing a good application prospect.