NOVELTY - Preparation of long life positive electrode includes taking aniline, adding hydrochloric acid solution, mixing to obtain aniline solution, adding into three-necked bottle, magnetically stirring, dissolving sodium dodecyl benzene sodium sulfonate in hydrochloric acid solution to obtain sodium dodecyl benzene sodium sulfonate solution, injecting to three necked bottle, uniformly stirring, adding potassium ammonium sulfate with hydrochloric acid solution, uniformly mixing to obtain ammonium persulfate solution, and dropping ammonium persulfate solution into bottle.    USE - Method for preparing long life positive electrode used for assembling lithium sulfur battery (claimed) for vehicle power cell, wind power generation, solar energy generation, tidal power generation, and electric power regulation.    ADVANTAGE - The product increases circulation life and high-rate discharge circuit of lithium sulfur battery.    DETAILED DESCRIPTION - Preparation of long life positive electrode comprises taking 20 g aniline, adding to 20 ml 0.5 mol/L hydrochloric acid solution, uniformly mixing to obtain aniline solution, adding into three-necked bottle, magnetically stirring, dissolving 2 g sodium dodecyl benzene sodium sulfonate in 5.74 ml 1 mol/L hydrochloric acid solution to obtain sodium dodecyl benzene sodium sulfonate solution, injecting to three necked bottle, uniformly stirring, adding 24.47 g potassium ammonium sulfate with 40 ml 1 mol/L hydrochloric acid solution, uniformly mixing to obtain ammonium persulfate solution, dropping ammonium persulfate solution into three necked flask, titrating at a speed of 0.5-0.7 ml/minute, reacting for 2 hours, filtering, drying at 80 degrees C for 24 hours to obtain conductive polyaniline; taking 1 g nitrogenous macroporous carbon contained sulfur material and 0.1-0.3 g conductive of polyaniline, mixing, uniformly grinding, adding 2 g N-methyl pyrrolidone as dispersant, modulating into paste, uniformly coating on aluminum film, vacuum drying at 70 degrees C for 2 hours to obtain polyaniline modified sulfur electrode; taking 10 g lithium hydroxide (LiOH), adding to 100 ml 5 wt.% perfluorinated sulfonic acid resin solution, stirring for 30 minutes, centrifugally separating excess LiOH to obtain lithium ion (Li+) type perfluorinated sulfonic acid resin solution; immersing modified sulfur electrode in Li+ type perfluorinated sulfonic resin solution for 2 hours, and air drying. An INDEPENDENT CLAIM is included for assembling lithium-sulfur battery comprising cutting positive electrode into 18 mm wafer, placing in commercially available button type battery shell, contacting positive electrode with aluminum substrate, placing 19 mm commercially available microporous polypropylene separator on positive electrode, performing lithium anode nitriding treatment on top of polypropylene membrane, placing 98% foam nickel piece having 18 mm diameter and thickness of 1 mm, adding 0.2 ml electrolyte, and sealing battery cover. The electrolyte comprises lithium bistrifluoromethylsulfonyl imide as solute, and dioxolane and ethylene glycol dimethyl ether as solvent. The volume ratio of dioxolane and ethylene glycol dimethyl ether is 1:1.