▎ 摘　　要

NOVELTY - Supercapacitor comprises first electrode, second electrode, porous separator disposed between the first and second electrodes, and ionic liquid electrolyte in physical contact with the two electrodes. At least one of the two electrodes comprises mesoporous structure formed of curved nano graphene platelets and multiple pores having a pore size of 2-25 nm. USE - Supercapacitor. ADVANTAGE - The pores are accessible to ionic liquid molecules, enabling the formation of large amounts of electric double layer charges in a supercapacitor, which exhibits an exceptionally high specific capacitance and high energy density. The graphene-based mesoporous electrode, in combination with an ionic liquid, provides a supercapacitor with an energy density greater than 100, preferably greater than 150 W.hour/kg based on the total electrode weight. This is achieved with the electric double layer mechanism alone, without a contribution from the pseudocapacitance mechanism. If a redox pair is formed, the capacitance can be further increased. The ionic liquids operate at greater than 3.5, preferably greater than 4.5 V in graphene electrode-based supercapacitor cells.