▎ 摘　　要

NOVELTY - Method for preparing a graphene based composition, comprises: subjecting a composition containing water and a graphene precursor to a mechanical treatment and chemical treatment for forming graphene; separating graphene from the mechanically and chemically treated composition for forming a graphene based composition; and mixing the graphene based composition with a first coupling agent that is capable of reacting with graphene. The graphene is formed by subjecting the composition comprising water and the graphene precursor to at least two mechanical treatments. USE - The method is useful for preparing a graphene based composition (claimed). ADVANTAGE - The method provides a highly conductive coating composition which can be prepared at low cost and under atmospheric conditions. The coated substrate is resistant to corrosion, preferably in the presence of corrosive electrolytes such as those used in batteries and fuel cells, and exhibits a low contact resistance and can be produced at low cost. The coated substrate is suitable to be used in electrochemical devices such as batteries and fuel cells. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) a method for manufacturing a coated substrate, comprising providing the graphene based composition on a metal or metal alloy substrate, and subjecting the coated metal or metal alloy substrate to a heat treatment of at least 100 degrees C; and (2) a coated substrate comprising a metal or metal alloy substrate provided with a graphene based coating comprising graphene and a first coupling agent that is coupled to graphene and to the metal or metal alloy substrate.