An advanced flower-like DBS-Co3O4 hierarchical microspheres with specific surface as electrochemical active sites have been synthesized from a novel DBS-intercalated Co(OH)(2) (DBS-Co(OH)(2)) flower spheres with atomically ultrathin Co(OH)(2) nanosheets. The hierarchical DBS-Co3O4 flower microspheres exhibit specific capacitance value of 1104.4 F g(-1) at a current density of 0.5 A g(-1) in 6 M KOH solution. Meanwhile, the 3D rGO aerogels are prepared by a facile method as negative electrode materials, and the specific capacitance of 213.3 F g(-1) can be achieved at a current density of 2 A g(-1). Therefore, both the DBS-Co3O4 microspheres with opened hierarchical honeycomb-like structures and 3D rGO aerogels with an interconnected pore network structures can be filled with electrolyte ions as double "ion-buffering reservoirs" in the charge-discharge process. Hence, the asymmetric supercapacitors of the double "ion-buffering reservoirs" are fabricated with the DBS-Co3O4 as positive electrode of promising Faradaic pseudocapacitors materials and the 3D rGO aerogels as the negative electrode of electrical double-layer capacitors materials, exhibiting a high energy density of 25.5 Wh kg(-1) at the power density of 400 kW kg(-1) with excellent cycling performance. (C) 2018 Elsevier Ltd. All rights reserved.