▎ 摘　　要

NOVELTY - Preparing flexible three-dimensional polypyrrole-nitrogen-doped carbon nanotube-graphene-graphene composite electrode involves designing the curved surface structure through software, stirring uniformly metal salt, photosensitive resin monomer and photoinitiator, using digital light processing technology to print, sintering, reducing to obtain the metal template, performing a chemical vapor deposition reaction on the obtained metal template, and adding dilute acid to remove the metal template. USE - Method for preparing flexible three-dimensional polypyrrole-nitrogen-doped carbon nanotube-graphene composite electrode used in supercapacitor (claimed). ADVANTAGE - The prepared electrode has high energy density and flexibility, and can improve its cycle performance and flexibility when applied to a supercapacitor. DETAILED DESCRIPTION - Preparing flexible three-dimensional polypyrrole-nitrogen-doped carbon nanotube-graphene composite electrode involves designing the curved surface structure through software, stirring uniformly metal salt, photosensitive resin monomer and photoinitiator, using digital light processing technology to print, sintering, reducing to obtain the metal template, performing a chemical vapor deposition reaction on the obtained metal template, adding dilute acid to remove the metal template, adding deionized water to clean the excess acid, obtaining nitrogen-doped graphene (NG) after freeze-drying, electroplating obtained nitrogen-doped graphene with nickel-cobalt hydroxide to obtain a nickel-cobalt hydroxide/graphene composite material, growing by a pyrolytic carbon source to obtain nitrogen-doped carbon nanotube/graphene composite, where the carbon source is melamine or dicyandiamide, and electroplating obtained polypyrrole (PPy) on the nitrogen-doped carbon nanotube (NCNT)/graphene composite (NG) material to obtain a flexible three-dimensional PPy-NCNT/NG electrode. INDEPENDENT CLAIMS are included for: 1. a flexible three-dimensional PPy-NCNT/NG electrode is prepared by the preparation method; and 2. an application method of flexible three-dimensional PPy-NCNT/NG electrode to a supercapacitor, which involves: (a) assembling symmetrical supercapacitor using two PPy-NCNT/NG electrode and polyvinyl alcohol/sulfuric acid gel as electrolyte;(b) adding 3 g polyvinyl alcohol into 20 ml deionized water, stirring vigorously at 85℃ until the solution becomes clear; (c) adding slowly 2 g concentrated sulfuric acid dropwise, stirring for 2 hours; (d) using the PPy-NCNT/NG electrode to absorb the gel electrolyte, assembling the two PPy-NCNT/NG electrodes after absorbing the gel electrolyte face to face; (e) packaging after the electrolyte is solidified, and testing to obtain the supercapacitor.