Background :
Renewable energies are in great demand because of the shortage of traditional fossil energy and
the associated environmental problems. Ni and Se-based materials are recently studied for energy storage and conversion
owing to their reasonable conductivities and enriched redox activities as well as abundance. However, their
electrochemical performance is still unsatisfactory for practical applications.
Objective:
To enhance the capacitance storage of Ni-Se materials via modification of their physiochemical properties with
Fe.
Methods:
A two-step method was carried out to prepare FeNi-Se loaded reduced graphene oxide (FeNi-Se/rGO). In the
first step, metal salts and graphene oxide (GO) were mixed under basic condition and autoclaved to obtain hydroxide
intermediates. As a second step, selenization process was carried out to acquire FeNi-Se/rGO composites.
Results:
X-ray diffraction measurements (XRD), nitrogen adsorption at 77K, scanning electron microscopy (SEM) and
transmission electron microscopy (TEM) were carried out to study the structures, porosities and the morphologies of the
composites. Electrochemical measurements revealed that FeNi-Se/rGO notably enhanced capacitance than the NiSe/G
composite. This enhanced performance was mainly attributed to the positive synergistic effects of Fe and Ni in the
composites, which not only had influence on the conductivity of the composite but also enhanced redox reactions at
different current densities.
Conclusion:
NiFe-Se/rGO nanocomposites were synthesized in a facile way. The samples were characterized
physicochemically and electrochemically. NiFeSe/rGO giving much higher capacitance storage than the NiSe/rGO
explained that the nanocomposites could be an electrode material for energy storage device applications.
A SnO2QDs/GO/PPY ternary composite film as positive and graphene oxide/charcoal as negative electrodes assembled solid state asymmetric supercapacitor for high energy storage applications
