Sandwich-Like Holey Graphene/PANI/Graphene Nanohybrid for Ultrahigh-Rate Supercapacitor

Hierarchically porous holey graphene/PANI/graphene nanohybrid is fabricated by adopting a facile twostep process in which PANI/graphene hybrid was first synthesized hydrothermally and then wrapped with a layer of holey graphene. The resulted sandwich-like structure cannot only promote electronic transmission and ionic diffusion, but also contribute to a prominent rate capability. A symmetric supercapacitor was assembled with the obtained holey graphene/PANI/graphene nanohybrid, exhibiting a maximum specific capacitance of 437 F-g(-1) at 1 AT(-1), an energy density of 55 WhIg(-1) at 900 W.kg(-1), an ultrahigh-rate performance (retained 43% capacitance at 100 A.g(-1)), as well as a long-term life (84% retention after 5000 loops at 10 A.g(-1)). The present work may provide an insight for designing high performance symmetric supercapacitor.