▎ 摘　　要

NOVELTY - Preparation of vanadium pentoxide/graphene composite, involves (i) preparing vanadium pentoxide aqueous dispersion, (ii) preparing oxidized graphene dispersion, (iii) dripping vanadium pentoxide aqueous dispersion into oxidized graphene dispersion, stirring to obtain vanadium pentoxide/graphene oxide dispersion as filtrate, (iv) subjecting filtrate to decompression and suction filtration, drying obtained solid film with microporous membrane, separating microporous membrane to obtain vanadium pentoxide/graphene composite membrane precursor, and (v) heating and cooling. USE - Preparation of vanadium pentoxide/graphene composite film used in flexible energy storage device (claimed) e.g. flexible capacitor device. ADVANTAGE - The flexible vanadium pentoxide/graphene oxide composite film is constructed by decompression and filtration method which is easy to control and operate. DETAILED DESCRIPTION - Preparation of vanadium pentoxide/graphene composite, involves (i) adding vanadium pentoxide to water, stirring and slowly dripping hydrogen peroxide solution, continuing the stirring process after addition of hydrogen peroxide solution, transferring the mixed solution to a reaction vessel, and performing hydrothermal reaction and cooling to obtain vanadium pentoxide aqueous dispersion, (ii) dispersing oxidized graphene in water to obtain oxidized graphene solution, centrifuging the graphene solution with a centrifuge and then taking a dispersion of intermediate layer into a dialysis bag for performing dialysis and obtaining oxidized graphene dispersion, (iii) dripping vanadium pentoxide aqueous dispersion into oxidized graphene dispersion, continually stirring to obtain vanadium pentoxide/graphene oxide dispersion as filtrate, (iv) subjecting the filtrate to decompression and suction filtration, drying solid film obtained by suction filtration together with microporous membrane, and separating the microporous membrane after drying to obtain vanadium pentoxide/graphene composite membrane precursor, (v) heating vanadium pentoxide/graphene composite film precursor for a certain period of time, and then cooling to room temperature, and obtaining vanadium pentoxide/graphene composite film.