Layer-dependent supercapacitance of graphene films grown by chemical vapor deposition on nickel foam

► High quality, large-area graphene films are synthesized on Ni foam using chemical vapor deposition. ► The number of graphene layers is adjusted by varying the rate of the cooling process. ► The capacitive properties of graphene films are related to the number of graphene layers. ► The specific capacitance of thinner graphene films is almost twice that of thicker ones and is stable up to 1000 cycles.