▎ 摘　　要

NOVELTY - Method for preparing button type casing capacitor with low-layer gauze-shaped nitrogen-doped graphene electrode involves (i) mixing flake graphite with a mixture of concentrated sulfuric acid and concentrated nitric acid, stirring, increasing the temperature to 60 degrees C for 7 hours, increasing the temperature to 90 degrees C for 40 minutes, naturally cooling the reacted solution to room temperature, mixing and reacting the cooled solution with ethanol intercalation solvent in a volume ratio of 22:(1-1.5), ultrasonically treating, adding diethanolamine to the intercalated solution in a volume ratio of (1-5):100 for nitrogen doping, putting the solution into an autoclave at 190-220 degrees C for 8-12 hours, performing suction filtration on the solution, washing with deionized water and filtering repeatedly until pH is 7, and freeze-drying to obtain nitrogen-containing graphene, and (ii) placing the nitrogen-containing graphene in a vacuum tube and embedding in a microwave oven with microwave power of 700-800 W and reacting to obtain the product. USE - The method is useful for preparing low-layer gauze-shaped nitrogen-doped graphene electrode and manufacturing of button casing type supercapacitor (claimed). ADVANTAGE - The method is simple, and prepares nitrogen-containing graphene with low raw material cost with porous and interconnected three-dimensional structure, large specific surface area and excellent conductivity to promote the rapid diffusion of electrolyte ion and increase the specific capacity. DETAILED DESCRIPTION - Method for preparing low-layer gauze-shaped nitrogen-doped graphene involves (i) mixing flake graphite with a mixture of concentrated sulfuric acid and concentrated nitric acid at 1:110 g/ml, stirring at 45 degrees C, where the mass ratio of potassium permanganate and graphite is 6:1, increasing the temperature to 60 degrees C for 7 hours, increasing the temperature to 90 degrees C for 40 minutes, naturally cooling the reacted solution to room temperature, mixing and reacting the cooled solution with ethanol intercalation solvent in a volume ratio of 22:(1-1.5), ultrasonically treating, adding diethanolamine to the intercalated solution in a volume ratio of (1-5):100 for nitrogen doping, putting the solution into an autoclave at 190-220 degrees C for 8-12 hours, performing suction filtration on the solution, washing with deionized water and filtering repeatedly until pH is 7, and freeze-drying to obtain nitrogen-containing graphene, and (ii) placing the nitrogen-containing graphene in a vacuum tube and embedding in a microwave oven with a microwave power of 700-800 W and reacting for 2-5 minutes to obtain the product. An INDEPENDENT CLAIM is included for a use of the nitrogen-doped graphene with low-layer gauze in manufacture of button casing type supercapacitor, involving (a) weighing active material nitrogen-containing graphene, conductive agent acetylene black and binder PTFE in mass ratio of 78:12:10, adding an appropriate amount of deionized water, adjusting into a slurry, coating the slurry evenly on the foamed nickel with phi of 10 mm, drying in vacuum at 120 degrees C for 1 hour, pressing into tablet, and weighing, and (b) assembling lower shell, current collector/positive electrode, diaphragm, negative electrode/current collector, gasket, spring, appropriate amount of 3 mol/l potassium hydroxide electrolyte and upper shell into a button-type super capacitor in order in a vacuum glove box, and sealing the supercapacitor with a pressure of 50 kg/cm2.