Materials Research Bulletin, Vol.51, 97-104, 2014
Nickel-cobalt layered double hydroxide ultrathin nanoflakes decorated on graphene sheets with a 3D nanonetwork structure as supercapacitive materials
The study reported a novel microwave heating reflux method for the fabrication of nickel-cobalt layered double hydroxide ultrathin nanoflakes decorated on graphene sheets (GS/NiCo-LDH). Ammonia and ethanol were employed as precipitant and reaction medium for the synthesis, respectively. The resulting GS/NiCo-LDH offers a 3D flowerclusters morphology with nanonetwork structure. Due to the greatly enhanced rate of electron transfer and mass transport, the GS/NiCo-LDH electrode exhibits excellent supercapacitive performances. The maximum specific capacitance was found to be 1980.7 F g(-1) at the current density of 1 A g(-1). The specific capacitance can remain 1274.7 F g(-1) at the current density of 15 A g(-1) and it has an increase of about 2.9% after 1500 cycles. Moreover, the study also provides a promising approach for the design and synthesis of metallic double hydroxides/graphene hybrid materials with time-saving and cost-effective characteristics, which can be potentially applied in the energy storage/conversion devices. (C) 2013 Elsevier Ltd. All rights reserved.
Keywords:Nickel-cobalt layered double hydroxides;Graphene;Hybrid;Microwave synthesis;Supercapacitors