▎ 摘　　要

NOVELTY - Sulfur-doped carbon-coated nickel nanomaterial comprises sulfur-doped carbon-coated nickel nanoparticles, and the sulfur-doped carbon-coated nickel nanoparticles contain metallic nickel cores and a sulfur-doped graphitized carbon layer shell coated on the surface of the metallic nickel core. The pore size of the sulfur-doped carbon-coated nickel nanomaterial has a mesoporous peak. USE - Sulfur-doped carbon-coated nickel nanomaterial. ADVANTAGE - The sulfur-doped carbon-coated nickel nanomaterial significantly improves the low-rate charge-discharge performance and specific capacity of the lithium-sulfur battery. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following: (1) a method for preparing sulfur-doped carbon-coated nickel nanomaterial, which involves forming a homogeneous solution with a nickel source, a polyvalent organic carboxylic acid, and a solvent, removing the solvent in the homogeneous solution to obtain a precursor, mixing and grinding the precursor with a solid sulfur source to form a mixture, and then subjecting the mixture to high-temperature pyrolysis under an inert atmosphere or a reducing atmosphere; (2) a lithium-sulfur battery positive electrode active material based on sulfur-doped carbon-coated nickel nanomaterials, where the positive electrode active material is a composite material containing sulfur-doped carbon-coated nickel nanomaterials, graphene, and elemental sulfur; and (3) a method for preparing lithium-sulfur battery cathode active material based on sulfur-doped carbon-coated nickel nanomaterials, which comprises mixing sulfur-doped carbon-coated nickel nanomaterials, graphene, and elemental sulfur to obtain a mixture, and subjecting the mixture to high temperature treatment at a temperature not lower than the melting temperature of sulfur under an inert atmosphere.