▎ 摘　　要

NOVELTY - Preparing graphene film, comprises dispersing graphene in isopropyl alcohol, then adding nano fiber bonding agent, filtering and vacuum drying, then transferring the obtained film from a substrate and rolling to obtain the graphene film. The nano fiber bonding agent comprises polyvinylidene fluoride and N-methylpyrrolidone. The concentration of the polyvinylidene fluoride in the nano fiber bonding agent is 0.02-0.03 g/ml. USE - The graphene film is useful in symmetrical and full batteries (all claimed) and in cathode of lithium metal battery. ADVANTAGE - The graphene film controls lithium metal and organic electrolyte interface and inhibits the growth of dendritic crystal, capable of safety circulation of lithium metal cathode, can control uniform nucleation of lithium ions, stabilizing the battery circulation and prolonging the service life of the battery. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: a graphene film prepared by the above-mentioned method. preparing a symmetrical battery. preparing a full battery.