▎ 摘　　要

NOVELTY - Preparation method of tungsten nitride nano-needle composite nitrogen-doped graphene nanosheet, involves dissolving 50-100 mg, preferably 60 mg tungsten chloride powder in 25-40 ml, preferably 30 ml ethanol as solvent to obtain solution (A), ultrasonically dispersing 1-5 mg, preferably 3 mg graphene oxide in 25-40 ml, preferably 30 ml water to obtain solution (B), stir-mixing solutions (A,B) for 0.5 hour at room temperature, adding the mixed solution to a reaction kettle, hydrothermally reacting at 180degrees Celsius for 3-12 hours, collecting the product to obtain a black precursor powder, and annealing the precursor powder at 600degrees Celsius for 2 hours in a tubular furnace under ammonia atmosphere. USE - Preparation of tungsten nitride nano-needle composite nitrogen-doped graphene nanosheet for lithium-sulfur battery separator (all claimed). ADVANTAGE - The tungsten nitride nano-needle composite nitrogen-doped graphene nanosheet separator middle layer prepared as a high-efficiency polysulfide catalyst and adsorbent improves lithium-sulfur battery performance. The method is simple, has good repeatability, is economical, and is feasible. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for the tungsten nitride nano-needle composite nitrogen-doped graphene nanosheet.