▎ 摘　　要

NOVELTY - The method involves providing a clean substrate followed by positively charged processing of a substrate surface, and preparing suspension of graphene with negative charges on a surface and the suspension of graphene with positive charges on another surface, respectively. A surface-treated substrate is immersed into the suspension of graphene with negative charges on surface for 5-20 minutes, so that the substrate is taken out. The substrate is washed, dried and immersed into the suspension of graphene with positive charges on surface for 5-20 minutes to obtain a graphene film precursor. USE - Method for preparing a graphene film utilized as a collector of super-capacitors and lithium-ion batteries. ADVANTAGE - The method enables preparing the graphene film with light and strongly conductive in simple manner, and controlling thickness of the film easily. DESCRIPTION OF DRAWING(S) - The drawing shows a photograph of a graphene film.