Preparation method for grading self-similar three-dimensional few layer porous graphene for high-performance super capacitor

The invention relates to a preparation method for grading self-similar three-dimensional few layer porous graphene for a high-performance super capacitor. The preparation method comprises the steps of mixing basic cupric carbonate and PMMA uniformly, heating under mixed atmosphere of hydrogen and inert gases, and pyrolyzing and reducing to obtain a mixture of copper and the PMMA; heating the mixture of the copper and the PMMA under the mixed atmosphere of the hydrogen and the inert gases, growing graphene to obtain copper @ graphene, and taking out a sample after a system is cooled to normal temperature; removing a copper template of the collected products by the sufficient amount of an oxidizing etching solution, filtering, washing repeatedly, and drying to obtain a product. The product obtained by the invention has the characteristics of large specific surface area, high electrical conductivity, excellent wettability, microporous-mesoporous-macroporous interconnected grading self-similar open pore structure, and the like, and the graphene is taken as an electrode material of the super capacitor, shows high-energy density, ultra high power density and excellent cycling stability in a water system and ionic liquid electrolyte.