3D porous layered double hydroxides grown on graphene as advanced electrochemical pseudocapacitor materials

Abstract

A 3D hybrid nickel-aluminum layered double hydroxide (NiAl-LDH)-graphene nanosheets (GNS) composite as a supercapacitor material has been fabricated by in situ deposition of LDH nanosheets on graphene oxide (GO) through a liquid phase deposition method. The results reveal that NiAl-LDH homogeneously grew on the surface of GNS as spacers to keep the neighboring sheets separate. Optimum effects could be achieved when feeding ratio, reaction time and temperature are tuned. The obtained porous GNS/NiAl-LDH composite exhibited high-capacitance performance with a specific capacitance of 1255.8 F g(-1) at a current density of 1 A g(-1) and 755.6 F g(-1) at 6 A g(-1), respectively. Moreover, the composite exhibited excellent cycling performance with an increase of 6% capacitance compared with the initial capacitance after 1500 cycle tests. Such high specific capacitance, rate capability and exceptional cycling ability of the composite offered great promise in energy storage device applications.