▎ 摘　　要

NOVELTY - Preparing graphene by recycling graphite cathode material using power battery comprises e.g. taking cathode material from fully discharged power battery, mixing with water, separating cathode active material from copper foil, taking out separated copper foil, stirring, allowing upper layer of turbid liquid to stand and re-adding water, filtering, drying, sieving to obtain graphite material, adding graphite material, potassium persulfate and phosphorus pentoxide with concentrated sulfuric acid, reacting, cooling, filtering and drying to obtain pre-oxidized graphite powder, adding pre-oxidized graphite powder to concentrated sulfuric acid, adding potassium permanganate, heating, adding deionized water, heating, cooling, adding hydrogen peroxide solution, adding concentrated hydrochloric acid, subjecting to oxidation, washing precipitate, centrifuging, dispersing precipitate, dialyzing, centrifuging dialysis solution, taking supernatant to obtain graphene oxide solution and drying. USE - The method is useful for preparing graphene by recycling graphite cathode material using power battery. ADVANTAGE - The method is simple and efficient, increases added value and promotes diversification of the industry. DETAILED DESCRIPTION - Preparing graphene by recycling graphite cathode material using power battery comprises (i) taking cathode material from fully discharged power battery, mixing cathode sheet and water in the ratio of 1:20-1:50, soaking at 10-50 degrees C for 1-10 minutes, separating cathode active material from copper foil and taking out separated copper foil; (ii) stirring the solution, allowing upper layer of turbid liquid to stand and re-adding water to make the volume of solution equal to the original volume; (iii) repeating steps (ii) 3-5 times, filtering, drying, grinding and sieving to obtain graphite material; (iv) adding 1 pts. wt. graphite material, 6 pts. wt. potassium persulfate and 8 pts. wt. phosphorus pentoxide, stirring and mixing, adding 30 pts. vol. concentrated sulfuric acid (98%), reacting, cooling, diluting, filtering and drying to obtain pre-oxidized graphite powder; (v) adding 1 pts. wt. pre-oxidized graphite powder to 24 pts. vol. concentrated sulfuric acid (98%) under an ice bath, adding 3 pts. wt. potassium permanganate slowly, heating to 35 degrees C, stirring for 2 hours, adding 50 pts. vol. deionized water, heating to 80 degrees C, stirring continuously for 0.5 hours, adding 140 pts. vol. deionized water, cooling, adding 2.5 pts. vol. hydrogen peroxide solution (30%), adding 125 pts. vol. concentrated hydrochloric acid (10%), subjecting to oxidation, washing precipitate and centrifuging three times, dispersing precipitate ultrasonically and dialyzing for one week; (vi) centrifuging dialysis solution by ultrasonication, centrifuging and taking supernatant to obtain graphene oxide solution; and (vii) drying graphene oxide solution and calcining at high temperature, where ratio of mass to volume 1 g: 1 ml.