▎ 摘　　要

NOVELTY - Production of graphene and/or graphene oxide involves providing a copper-based sheet (203) coated on at least one side with a carbonaceous material (201), providing a bath comprising an aqueous solution comprising a salt of at least one ion selected from lithium, sodium, potassium, magnesium or calcium in which bath a electrode (E1) is arranged, feeding the copper-based sheet into the bath, applying a voltage (V1) between the copper-based sheet and the electrode (E1), such that the at least one ion is intercalated into the carbonaceous material, applying a voltage (V2), reversed as compared to the voltage (V1), between the copper-based sheet and the electrode (E1), such that graphene and/or graphene oxide is exfoliated from the carbonaceous material. USE - Production of graphene and/or graphene oxide for forming graphene materials used in electrical and electrochemical applications. ADVANTAGE - The method produces graphene and/or graphene oxide which is pure, high quality crystalline and has excellent conductivity and good mechanical properties. DETAILED DESCRIPTION - Production of graphene and/or graphene oxide involves providing a copper-based sheet (203) coated on at least one side with a carbonaceous material (201), providing a bath (215) comprising an aqueous solution comprising a salt of at least one ion selected from lithium (Li+), sodium (Na+), potassium (K+), magnesium (Mg2+) or calcium (Ca2+) in which bath a electrode (205) is arranged, feeding the copper-based sheet into the bath, applying a voltage (V1) between the copper-based sheet and the electrode (205), such that the at least one ion is intercalated into the carbonaceous material, applying a voltage (V2), reversed as compared to the voltage (V1), between the copper-based sheet and the electrode (205), such that graphene and/or graphene oxide is exfoliated from the carbonaceous material. INDEPENDENT CLAIMS are included for the following: ystem for producing graphene and/or graphene oxide, which comprises a copper-based sheet coated on one side with a carbonaceous material, a bath (215) comprising an aqueous solution comprising a salt of at least one ion selected from lithium (Li+), sodium (Na+), potassium (K+), magnesium (Mg2+) or calcium (Ca2+), a feeding device for feeding the copper-based sheet into the bath, a electrode (205) configured to be arranged in the bath, a voltage controlling unit for applying voltage (V1) and (V2) between the copper-based sheet and the electrode (205), the voltage (V2) is reversed as compared to the voltage (V1); and graphene material, which is formed as crystalline, self-supporting hexagonal flakes having an average size of at least 1 μ m2. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the system. 201Carbonaceous material 203Copper-based sheet 205Electrode 211,219Rollers 215Bath 227Filter