▎ 摘　　要

NOVELTY - A graphene film comprises 8.2-8.6% azane doping concentration, and has density of 1.67-1.71 gcm-3. USE - Graphene film is used for electrode for electric vehicle and portable electronic device. ADVANTAGE - The graphene film has high density and ion transmission property, and provides lightweight electrode having high specific capacity of 413F cm-3, mass specific capacity of 252 Fg-1 and energy density of 138 W.h.L-1. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of graphene film, which involves scraping a film with 10-20 mgg-1 graphene oxide dispersion, such that film thickness is 0.5-6 mm, transferring the obtained graphene oxide film to a coagulation bath, soaking for more than 0.5 hour, hydrothermally reacting at 180 degrees C for 0.5-18 hours, washing with deionized water and drying.