- - Preparation method for Nitrogen doped graphene having a polymer coating-sulfur complexes the prepared complexes and lithium-sulfur battery using the same

摘要

The present invention relates to a process for producing a nitrogen-doped graphene-sulfur composite having a polymer coating layer, a composite produced thereby, and a lithium-sulfur secondary battery using the same. More specifically, the present invention relates to a process for preparing a graphene oxide suspension, comprising: 1) dispersing graphite oxide in distilled water to prepare a graphene oxide suspension; 2) adding a conductive polymer containing nitrogen to the suspension, and hydrothermally synthesizing the graphene oxide to prepare a conductive polymer-coated graphene oxide; 3) heat treating the conductive polymer-coated graphene oxide to prepare a nitrogen-doped graphene sheet; 4) adding the nitrogen-doped graphene sheet to a solvent containing sulfur, mixing and dispersing the mixture, and then heat-treating to prepare a nitrogen-doped graphene sheet-sulfur composite; And 5) forming a polymer coating layer on the surface of the nitrogen-doped graphene sheet-sulfur composite. A method for producing a nitrogen-doped graphene-sulfur composite having a polymer coating layer is disclosed. According to the present invention, the conductivity of the electrode is ensured by using the graphene having excellent electrical conductivity, while the sulfur is contained in the polymer coating layer and the graphene sheet doped with nitrogen, whereby polysulfides are eluted by the solution reaction during charging and discharging The effect can be suppressed and the capacity reduction and the side reaction thereof can be minimized, thereby improving the electrochemical characteristics.