Study on Preparation and Electrochemical Performance of rGO/MoS_2-x Material Based on Defect Engineering

The commercial application of lithium-sulfur batteries（LSBs） has been seriously hindered by the shuttle effect of lithium polysulfide（Li PSs） and their slow redox kinetics. In response to the above problems, rGO/MoS₂ composite material was prepared by hydrothermal method, and based on defect engineering strategy, abundant sulfur vacancies were introduced into the material when the material was annealed at 400, 500 ℃ for 3 h to improve the performance of LSBs. The results show that the absorption and redox reaction kinetics of Li PSs can be adjusted by optimizing sulfur vacancies to higher concentrations. In addition, the rich sulfur defect vacancies in the composite material can accelerate the separation of electrons and holes, which is easy to reduce the activation energy barrier of the reaction process. At the same time, it is beneficial to the adsorption and electron transfer of Li PSs and promote the occurrence of catalytic reactions. Due to these reasons, LSBs based on rGO/MoS_2-x -500 modified separators exhibit a satisfactory discharge specific capacity of 1016 m Ah/g at 1 C and a low capacity decay rate of 0.0618% after 900 cycles.