초록 |
Graphene is a promising active material for supercapacitor (SC) by forming electric double-layer at the interface between the material and electrolyte. We introduce a novel synthetic approach of mesoporous graphene (m-G) based on self-assembled mesoporous structures prepared by poly(styrene)-b-poly(2-vinylpyridine) copolymer (PS-b-P2VP) providing both building block of catalytic template and carbon source. The sequential heat treatment of carbonization and catalytic pyrolysis enables synthesis of m-G without collapsing the preformed mesoporous structures. The m-G to showed high ion accessibility and facile contact of large amounts of ions to graphene surface. When we used ionic liquids (ILs) as electrolytes, m-G based SC showed stable electrochemical behavior in a wide range of operation voltage (0 V ~ 4 V), a high specific capacitance (15.4 F/g at 0.2 A/g), a high-power density of 800 W/kg at energy density of 68.4 Wh/kg, and excellent cycle stability. |