Facile fabrication of GNS/NiCoAl-LDH composite as an advanced electrode material for high-performance supercapacitors

Graphene nanosheet and ternary-component nickel cobalt aluminum-layered double hydroxide composite (GNS/NiCoAl-LDH) has been successfully fabricated by a facile assembly method. The NiCoAl-LDH flakes homogeneously distribute on the surfaces of GNS, forming a three-dimensional nanosheets array structure. Electrochemical properties are characterized by cyclic voltammetry, galvanostatic charge/discharge measurements, and electrochemical impedance spectroscopy. The influence of GNS doped content on the electrochemical behavior of GNS/NiCoAl-LDH composite has been studied. The result indicate that when the GNS content is 3.0 %, the GNS/NiCoAl-LDH composite electrode exhibits a maximum specific capacitance of 1,962 F g−1 at 1 A g−1 and remains at 1,180 F g−1 even at a high current density of 10 A g−1. After 2,000 cycles, the composite electrode keeps a remarkable specific capacitance of 1,260 F g−1 at 5 A g−1. The enhanced electrochemical performances of the composite are attributed to the highly electron conductivity and large specific surface area of the graphene nanosheets. This newly designed GNS/NiCoAl-LDH composite may offer a promising electrode material for supercapacitors.