▎ 摘　　要

NOVELTY - The capacitor (10) has an electrolyte containing an ionic liquid containing a cation having a complex aromatic ring. A separator (4) is interposed between an electrode containing an active material, and other electrode containing other active material. A reduced type graphene oxide is provided with a fold-shaped structure in which a graphene sheet having pleats is bent. The radius of curvature of the bent portion in the bending structure of the graphene sheet is in the range of 10-1000 nm. The cation contains an imidazolium cation. USE - Capacitor using graphene for electrode material. ADVANTAGE - The capacitor has high energy density. DESCRIPTION OF DRAWING(S) - The drawing shows a cross sectional view of the capacitor. (Drawing includes non-English language text) 1Capacitor element 2First electrode 3Second electrode 4Separator 10Capacitor