▎ 摘　　要

NOVELTY - Preparing graphene composite material functional film involves mixing the graphene and biological micro-molecule reagent with solvent N-methyl pyrrolidone, stirring and dispersing uniformly for controlling viscosity at 1000-10000 centipoise to obtain composite material slurry, where biological micro-molecule reagent is dithiothreitol, vitamin C, glutathione or beta -mercapto ethanol and ratio of graphene and biological micro-molecule reagent is 2-1:0.2. The obtained composite material slurry is coated with lithium-sulphur battery anode material. USE - Method for preparing graphene composite material functional film (claimed). ADVANTAGE - The method enables to prepare graphene composite material functional film that has moderate reaction conditions, large scale production, inhibits shuttle effect, improves coulomb efficiency and cycle stability of the lithium-sulphur battery, in simple manner. DETAILED DESCRIPTION - Preparing graphene composite material functional film involves mixing the graphene and biological micro-molecule reagent with solvent N-methyl pyrrolidone, stirring and dispersing uniformly for controlling viscosity at 1000-10000 centipoise to obtain composite material slurry, where biological micro-molecule reagent is dithiothreitol, vitamin C, glutathione or beta -mercapto ethanol and ratio of graphene and biological micro-molecule reagent is 2-1:0.2. The obtained composite material slurry is coated with lithium-sulphur battery anode material of 100-400 mm thickness and then dried at 40-60 degrees C to obtain graphene composite material functional film. An INDEPENDENT CLAIM is included for a method for preparing porous carbon nano-tube cathode material, which involves: (A) adding commercial carbon nano-tube to the material liquid of 1:500-1000 ratio into water/concentrated sulfuric acid/nitric acid of ratio 4:3:1, refluxing at 120-160 degrees C for 3-5 hours, cooling, adding super-pure water for decompressing and filtering until the filtrate pH is 7 and then drying at 80-120 degrees C in oven to obtain purified carbon nano tube; (B) placing obtained purified carbon nano tube in the quartz boat, transferring the quartz boat into the tubular quartz furnace, placing de-ionized water into ultrasonic sprayer which is connected with the tubular quartz furnace, under argon gas, heating tubular quartz furnace at 700-950 degrees C, opening the ultrasonic nebulizer and adjusting power to 20-60 volt-ampere with 0.2-1.0 liter per minute for 5-20 minutes and then cooling at room temperature to obtain porous carbon nano tube; (C) mixing obtained porous carbon nano tube with elemental sulfur in 1:1-4 ratio, mixing mixture uniformly with material liquid of 1:10 ratio in carbon sufide, stirring at 10-30 degrees C and placing mixture at 120-160 degrees C to volatilize carbon sufide for 8-12 hours in oven and then cooling at room temperature to obtain porous carbon nano-tube composite material; and (D) mixing obtained porous carbon nano-tube composite material with carbon black, Polyvinylidene fluoride with 1:0.05-0.25:0.05-0.15 ratio, adding N-methyl pyrrolidone, stirringand dispersing ultrasonically for controlling viscosity at 1000-10000 centipoise to obtain slurry, coating obtained slurry uniformly on current collector aluminum foil with 150-400 mm thickness, and transferring the foil to oven at 40-60 degrees C for dying to obtain porous carbon nano-tube cathode material.