▎ 摘　　要

NOVELTY - Preparation of sulfonated graphene/manganese dioxide/poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid three-phase composite electrode involves preparing sulfonated graphene dispersion, coating sulfonated graphene dispersion on indium tin oxide (ITO) glass to obtain sulfonated graphene electrode, reacting electrode electrochemically in manganese(II) sulfate (MnSO4) solution to obtain sulfonated graphene/manganese dioxide composite electrode, preparing 3,4-ethylenedioxythiophene-styrene sulfonic acid in sodium sulfate solution, and reacting obtained electrode in obtained solution. USE - Method for preparing sulfonated graphene/manganese dioxide/poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid three-phase composite electrode (claimed) used for vanadium battery. ADVANTAGE - The electrode has low vanadium ion crystallization rate and excellent permeability rate which ensures long service life of battery. DETAILED DESCRIPTION - Preparation of sulfonated graphene/manganese dioxide/poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid three-phase composite electrode comprises: (A) dissolving potassium persulfate and phosphorus pentoxide in concentrated sulfuric acid, adding graphite, reacting at 80 degrees C for 4-5 hours, cooling reaction mixture to room temperature, filtering, drying residue, mixing residue with concentrated sulfuric acid, cooling to 0-5 degrees C, adding potassium permanganate at 1:1 molar ratio, reacting for 2-3 hours in similar temperature, adding hydrogen peroxide to form yellow precipitate, filtering, and drying residue; (B) dissolving p-aminobenzenesulfonic acid in 2 wt.% sodium hydroxide solution, cooling to 0 degrees C, adding sodium nitrite at 2:1 mass ratio, adding hydrochloric acid dropwise at 20:1 molar ratio to form white precipitate, filtering mixture, and drying precipitate; (C) mixing obtained yellow precipitate homogeneously with sodium borohydride (NaBH4) at 1:1.5 molar ratio, pouring obtained mixture into water, adding obtained white precipitate at white precipitate-yellow precipitate mass ratio of 1:1.2, reacting mixture at not greater than 0 degrees C for 5-6 hours, and adding hydrazine hydrate at yellow precipitate-hydrazine hydrate molar ratio of 1:1 to obtain sulfonated graphene dispersion; (D) coating obtained sulfonated graphene dispersion uniformly on ITO glass to obtain sulfonated graphene electrode, soaking obtained electrode in 0.1 mol/L MnSO4 solution to serve as working electrode with silver (Ag)/silver chloride (AgCl) as reference electrode and platinum wire as counter electrode, and reacting at room temperature with 1 V voltage for 5-6 minutes to obtain sulfonated graphene/manganese dioxide composite electrode; and (E) dissolving 0.05 mol/L 3,4-ethylenedioxythiophene-styrene sulfonic acid in 0.1 mol/L sodium sulfate solution to obtain supporting electrolyte, immersing obtained sulfonated graphene/manganese dioxide electrode to serve as working electrode with Ag/AgCl reference electrode and platinum wire counter electrode, reacting at room temperature with 1 V voltage for 5-6 minutes to obtain composite electrode.