▎ 摘　　要

NOVELTY - Preparing (M1) graphene-graphene fused material (100), comprises (a) forming many nano graphene-metal composites comprised of nano graphene and nano metal (12) provided on a surface of the nano graphene for bonding between nano graphenes (11, 11'), (b) forming polydopamine layer (13) on outer surfaces of nano graphene-metal composites, and (c) thermally treating nano graphene-metal composites to prepare graphene-graphene fused material in which nano graphene-metal composites are melted and bonded to each other by nano metal provided on nano graphene-metal composites. USE - The method is useful for preparing a graphene-graphene fused material, which is used to prepare graphene-substrate composite (claimed) that is used in an electrode material of lithium secondary battery and ultra-high capacity capacitor. ADVANTAGE - The method: is simple and provides graphene-graphene fused material that utilizes nano graphene and nano metal that exhibits enhanced performances in thermal conductivity, electrical conductivity and gas barrier properties; utilizes the polydopamine layer at low concentrations which improves bonding properties between the graphenes, thus increasing bonding strength between the graphenes and increasing the dispersibility and content of graphene-graphene fused material in the substrate; provides graphene-substrate composite that exhibits enhanced performances in electrical conductivity and thermal conductivity. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) preparing (M2) a graphene-substrate composite, comprising the steps (a)-(c) as above per se, and pulverizing the prepared graphene-graphene fused material and dispersing the pulverized graphene-graphene fused material in a substrate; (2) a graphene-graphene fused material, comprising many nano graphenes, a nano metal provided on outer surfaces of the nano graphenes for melt bonding between the nano graphenes and a polydopamine layer at least provided on an outer surface of the nano metal; and (3) a graphene-substrate composite, comprising a substrate and the graphene-graphene fused material dispersed in the substrate. DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a graphene-graphene fused material bonded in a longitudinal direction of the graphene. Two nano graphenes (11, 11') Nano metal (12) Polydopamine layer (13) Graphene-graphene fused materials (100)