Melamine-based externally-coated porous carbon-sulfur composite material as well as preparation method and application thereof

The invention discloses a melamine-based externally-coated porous carbon-sulfur composite material as well as a preparation method and application thereof. The melamine-based externally-coated porouscarbon-sulfur composite material takes melamine, pyrrole and sulfur as raw materials, and is obtained through a hydrothermal method, a low-temperature liquid-phase polymerization method and a meltingmethod, wherein the sulfur content is 65-75%. The preparation method of the melamine-based externally-coated porous carbon-sulfur composite material comprises the following steps of synthesizing melamine phosphate through the hydrothermal method to prepare melamine-based porous carbon, then preparing the melamine-based externally-coated porous carbon through the low-temperature liquid-phase polymerization method, and finally preparing the activated melamine-based externally-coated porous carbon-sulfur composite material through the melting method. When the material is used as the positive electrode of a lithium-sulfur